code: def license(self, value=None):
          
          if not (value is None):
              if (self.metadatatype == "native"):
                  self.metadata['license'] = value
              else:
                  self._license = value
          if (self.metadatatype == "native"):
              if 'license' in self.metadata:
                  return self.metadata['license']
              else:
                  return None
          else:
              return self._license
docs: No arguments: Get the document's license from metadata
             Argument: Set the document's license in metadata