Get the document selector with the defined shard keys.
@example Get the selector for the shard keys.
person.shard_key_selector
@return [ Hash ] The shard key selector.
@since 2.0.0
def shard_key_selector
{}.tap do |selector|
shard_key_fields.each do |field|
selector[field.to_s] = send(field)
end
end
end