code: def from_string(cls, content, position=1, file_id=None):
          
          if file_id is None:
              file_id = 'inlined_input'
          return cls(FileMetadata(file_id, position), content)
docs: Convenience method to create a file from a string.
  
          This file object's metadata will have the id 'inlined_input'.
  
          Inputs
          ------
          content -- the content of the file (a string).
          position -- (default 1) rank among all files of the model while parsing
              see FileMetadata
          file_id -- (default 'inlined_input') the file_id that will be used by
              kappa.