Demonstrators holding Serbian flags attend an anti-government protest in central Belgrade, Serbia, December 29, 2018. REUTERS/Marko Djurica

The rising full moon is seen behind Christmas lights in Skopje, Macedonia December 25, 2018. REUTERS/Ognen Teofilovski

A priest holds a cross after a mass on Christmas at St George Chaldean Catholic Church in Baghdad, Iraq December 25, 2018. REUTERS/Thaier Al-Sudani

A woman places figures at a nativity scene display during Christmas day preparations at the Saint Benoit church in Kinshasa, Democratic Republic of Congo, December 24, 2018. REUTERS/Baz Ratner

Moon is seen next to a Christmas tree in the city of Fuheis near Amman, Jordan, December 23, 2018. Picture taken December 23, 2018. REUTERS/Muhammad Hamed

The rising full moon is seen behind Christmas lights in Valletta, Malta December 23, 2018. REUTERS/Darrin Zammit Lupi TPX IMAGES OF THE DAY

The rising full moon is seen behind Christmas lights in Valletta, Malta December 23, 2018. REUTERS/Darrin Zammit Lupi

The rising full moon is seen behind Christmas lights in Valletta, Malta December 23, 2018. REUTERS/Darrin Zammit Lupi

The rising full moon is seen behind Christmas lights in Valletta, Malta December 23, 2018. REUTERS/Darrin Zammit Lupi

A man dressed as Santa Claus pedals passengers in a rickshaw along Oxford Street, in London, Britain December 23, 2018. REUTERS/Hannah McKay

The Frauenkirche (Church of our Lady), the City Hall and the Christmas market on Marienplatz are seen behind raindrops on a fence in Munich, Germany, December 23, 2018. REUTERS/Andreas Gebert

The Frauenkirche (Church of our Lady), the City Hall and the Christmas market on Marienplatz are seen behind raindrops on a fence in Munich, Germany, December 23, 2018. REUTERS/Andreas Gebert

The Frauenkirche (Church of our Lady), the City Hall and the Christmas market on Marienplatz are seen behind raindrops on a fence in Munich, Germany, December 23, 2018. REUTERS/Andreas Gebert

A Palestinian woman displays a wax ornament she made for sale during Christmas season, in Ramallah the Israeli-occupied West Bank December 23, 2018. REUTERS/Raneen Sawafta

Iraqi Christians pray during Mass at St George Chaldean Catholic Church in Baghdad, Iraq December 23, 2018. REUTERS/Thaier Al-Sudani

An Iraqi Christian woman prays during Mass at St George Chaldean Catholic Church in Baghdad, Iraq December 23, 2018. REUTERS/Thaier Al-Sudani

Iraqi Christians pray during Mass at St George Chaldean Catholic Church in Baghdad, Iraq December 23, 2018. REUTERS/Thaier Al-Sudani

An Iraqi Christian prays during Mass at St George Chaldean Catholic Church in Baghdad, Iraq December 23, 2018. REUTERS/Thaier Al-Sudani

Iraqi Christians pray during Mass at St George Chaldean Catholic Church in Baghdad, Iraq December 23, 2018. REUTERS/Thaier Al-Sudani

Christian children play outside their home they returned to after being displaced by Islamic State militants in al-Hamdaniya, Iraq December 21, 2018. Picture taken December 21, 2018. REUTERS/Khalid al-Mousily

A Christian family decorates a Christmas tree at their home in al-Hamdaniya, Iraq December 22, 2018. Picture taken December 22, 2018. REUTERS/Khalid al-Mousily

Christians shop at a store selling Christmas decorations in al-Hamdaniya, Iraq December 21, 2018. Picture taken December 21, 2018. REUTERS/Khalid al-Mousily

Iraqis shop at a store selling Christmas decorations in Mosul, Iraq December 22, 2018. Picture taken December 22, 2018. REUTERS/Khalid al-Mousily

A general view of the St. Patrick's Cathedral is seen with its Christmas illumination in Karachi, Pakistan December 22, 2018. REUTERS/Akhtar Soomro

Santa Claus figures are seen among Christmas decorations and lights outside a house in Attard, Malta December 19, 2018. REUTERS/Darrin Zammit Lupi

People look at Christmas decoration at the Christmas market in front of the city hall in Vienna, Austria December 19, 2018. REUTERS/Leonhard Foeger

A general view shows the Christmas market in front of the city hall in Vienna, Austria December 19, 2018. REUTERS/Leonhard Foeger

A general view shows the Christmas market in front of the city hall in Vienna, Austria December 19, 2018. REUTERS/Leonhard Foeger

A boy wearing Santa Claus outfit watches a large fish tank at Sunshine Aquarium in Tokyo, Japan, December 18, 2018. REUTERS/Issei Kato

People gather in the street with Christmas and New Year lights in the background in Moscow, Russia December 17, 2018. REUTERS/Maxim Shemetov

An aerial view shows a climber, dressed as Santa Claus, who decorates a 57-metre-high Christmas tree in a park on Tatyshev Island, located in the middle of the Yenisei River in the Siberian city of Krasnoyarsk, Russia December 17, 2018. REUTERS/Ilya Naymushin TPX IMAGES OF THE DAY

An aerial view shows a climber, dressed as Santa Claus, who decorates a 57-metre-high Christmas tree in a park on Tatyshev Island, located in the middle of the Yenisei River in the Siberian city of Krasnoyarsk, Russia December 17, 2018. REUTERS/Ilya Naymushin

A climber, dressed as Santa Claus, stands inside a crane cradle while decorating a 57-metre-high Christmas tree in a park on Tatyshev Island, located in the middle of the Yenisei River in the Siberian city of Krasnoyarsk, Russia December 17, 2018. REUTERS/Ilya Naymushin

An aerial view shows a climber, dressed as Santa Claus, who decorates a 57-metre-high Christmas tree in a park on Tatyshev Island, located in the middle of the Yenisei River in the Siberian city of Krasnoyarsk, Russia December 17, 2018. REUTERS/Ilya Naymushin

Participants dressed as Santa Claus take part in the annual race known as "Run Santa Run" at Fundidora Park in Monterrey, Mexico December 16, 2018. REUTERS/Daniel Becerril TPX IMAGES OF THE DAY

A figure of Santa Claus using a parachute is seen among Christmas decorations and lights on the facade of a house in San Gwann, Malta December 16, 2018. REUTERS/Darrin Zammit Lupi TPX IMAGES OF THE DAY

A house decorated with Christmas lights and designs is seen in San Gwann, Malta December 16, 2018. REUTERS/Darrin Zammit Lupi

A figure of Santa Claus using a parachute is seen among Christmas decorations and lights on the facade of a house in San Gwann, Malta December 16, 2018. REUTERS/Darrin Zammit Lupi

People walk beneath Christmas lights in the centre of Valletta, Malta December 16, 2018. REUTERS/Darrin Zammit Lupi

Participants dressed as Santa Claus take part in the annual race known as "Run Santa Run" at Fundidora Park in Monterrey, Mexico December 16, 2018. REUTERS/Daniel Becerril

Christmas decorations hang from trees in a forest near Birnam, Scotland, Britain, December 16, 2018. REUTERS/Russell Cheyne

Christmas decorations hang from trees in a forest near Birnam, Scotland, Britain, December 16, 2018. REUTERS/Russell Cheyne

A Christmas decoration hangs from a tree in a forest near Birnam, Scotland, Britain, December 16, 2018. REUTERS/Russell Cheyne

A view shows festive decorations and lights for the upcoming New Year and Christmas season near a tower of the Kremlin in central Moscow, Russia December 14, 2018. REUTERS/Tatyana Makeyeva

Women knit during a Christmas workshop to teach embroidery in the northern Israeli city of Nazareth, December 6, 2018. Picture taken December 6, 2018. REUTERS/Ammar Awad

Women cross-stitch during a Christmas workshop to teach embroidery and handicrafts in the northern Israeli city of Nazareth, December 6, 2018. Picture taken December 6, 2018. REUTERS/Ammar Awad

A woman adjusts decorations during a Christmas workshop to teach embroidery in the northern Israeli city of Nazareth December 6, 2018. Picture taken December 6, 2018. REUTERS/Ammar Awad

Christmas decorations are seen in the garden that belongs to Serge Hennebel, nicknamed "Elf Serge", which has been transformed into a Christmas village and adorned with hundreds of lights, in Mille, Belgium December 9, 2018. Picture taken December 9, 2018. REUTERS/Yves Herman

A Palestinian worker carves a figurine for sale during Christmas season, at a workshop in Bethlehem in the occupied West Bank, December 10, 2018. REUTERS/Raneen Sawafta

The Frauenkirche (Church of Our Lady) is pictured at a Christmas Market in Dresden, Germany, December 9, 2018. REUTERS/Fabrizio Bensch

Toys depicting Santa Claus are seen at the Christmas market in Tallinn, Estonia December 9, 2018. REUTERS/Ints Kalnins

Pre-bagged Christmas trees lie in forest at Wicklow Way Christmas tree farm in Roundwood, Ireland, December 9, 2018. REUTERS/Clodagh Kilcoyne

The Capitol Christmas Tree, an 80-foot Noble Fir from the Willamette National forest in Oregon, is seen lit on the West Front Lawn of the U.S. Capitol in Washington, U.S., December 6, 2018. REUTERS/Yuri Gripas

The Capitol Christmas Tree, an 80-foot Noble Fir from the Willamette National forest in Oregon, is lit on West Front Lawn of the U.S. Capitol in Washington, U.S., December 6, 2018. REUTERS/Yuri Gripas

The Capitol Christmas Tree, an 80-foot Noble Fir from the Willamette National forest in Oregon, is lit on West Front Lawn of the U.S. Capitol in Washington, U.S., December 6, 2018. REUTERS/Yuri Gripas

The Capitol Christmas Tree, an 80-foot Noble Fir from the Willamette National forest in Oregon, is lit on West Front Lawn of the U.S. Capitol in Washington, U.S., December 6, 2018. REUTERS/Yuri Gripas

A Christmas tree made of plastic chairs is pictured at the Macroplaza in Monterrey, Mexico November 26, 2018. Picture taken November 26, 2018. REUTERS/Daniel Becerril

A Christmas tree made of plastic chairs is pictured at the Macroplaza in Monterrey, Mexico November 26, 2018. Picture taken November 26, 2018. REUTERS/Daniel Becerril

A Christmas tree made of plastic chairs is pictured at the Macroplaza in Monterrey, Mexico November 26, 2018. Picture taken November 26, 2018. REUTERS/Daniel Becerril

A woman looks at Christmas decorations in a shop in Rome, Italy, December 4, 2018. REUTERS/Max Rossi