code: def set_file_spdx_id(self, doc, spdx_id):
          
          if self.has_package(doc) and self.has_file(doc):
              if not self.file_spdx_id_set:
                  self.file_spdx_id_set = True
                  if validations.validate_file_spdx_id(spdx_id):
                      self.file(doc).spdx_id = spdx_id
                      return True
                  else:
                      raise SPDXValueError('File::SPDXID')
              else:
                  raise CardinalityError('File::SPDXID')
          else:
              raise OrderError('File::SPDXID')
docs: Sets the file SPDX Identifier.
          Raises OrderError if no package or no file defined.
          Raises SPDXValueError if malformed value.
          Raises CardinalityError if more than one spdx_id set.