code: def write_document(document, out, validate=True):
      
      
      if validate:
          messages = []
          messages = document.validate(messages)
          if messages:
              raise InvalidDocumentError(messages)
  
      writer = Writer(document, out)
      writer.write()
docs: Write an SPDX RDF document.
      - document - spdx.document instance.
      - out - file like object that will be written to.
      Optionally `validate` the document before writing and raise
      InvalidDocumentError if document.validate returns False.