docs: def find_descriptor_schemas(self, schema_file):
          """Find descriptor schemas in given path."""
          if not schema_file.lower().endswith(('.yml', '.yaml')):
              return []
  
          with open(schema_file) as fn:
              schemas = yaml.load(fn, Loader=yaml.FullLoader)
          if not schemas:
              self.stderr.write("Could not read YAML file {}".format(schema_file))
              return []
  
          descriptor_schemas = []
          for schema in schemas:
              if 'schema' not in schema:
                  continue
  
              descriptor_schemas.append(schema)
  
          return descriptor_schemas