def find_id_metadata(collection_name)
    collection_data = @collections.fetch(collection_name)
    class_metadata = @class_metadata.fetch(collection_data[:type].to_s)
    key = class_metadata.select{|k,h| h.is_key }.collect{|k,h| h.name }[0]
    class_metadata[key]
  end
def find_id_metadata(collection_name)
    collection_data = @collections.fetch(collection_name)
    class_metadata = @class_metadata.fetch(collection_data[:type].to_s)
    key = class_metadata.select{|k,h| h.is_key }.collect{|k,h| h.name }[0]
    class_metadata[key]
  end
Finds the metadata associated with the given collection's first id property
 Remarks: This is used for single item lookup queries using the ID, e.g. Products(1), not complex primary keys

 @param [String] collection_name the name of the collection