code: def metadata_matches(self, query={}):
          
          result = len(query.keys()) > 0
          for key in query.keys():
              result = result and query[key] == self.metadata.get(key)
  
          return result
docs: Returns key matches to metadata
  
          This will check every key in query for a matching key in metadata
          returning true if every key is in metadata.  query without keys
          return false.
  
          Args:
              query(object): metadata for matching
  
          Returns:
              bool:
                  True: when key count in query is > 0 and all keys in query in
                      self.metadata
                  False: if key count in query is <= 0 or any key in query not
                      found in self.metadata