code: def update_dependent_files(self, prev_commands=[]):
          
          for command in prev_commands:
              for my_input in self.input_parts:
                  for their_output in command.output_parts:
                      if their_output == my_input:
                          my_input.filename = their_output.eval()
docs: Update the command's dependencies based on the evaluated input and
          output of previous commands.