code: def execute_code_block(elem, doc):
      
      command = select_executor(elem, doc).split(' ')
      code = elem.text
      if 'plt' in elem.attributes or 'plt' in elem.classes:
          code = save_plot(code, elem)
      command.append(code)
      if 'args' in elem.attributes:
          for arg in elem.attributes['args'].split():
              command.append(arg)
  
      cwd = elem.attributes['wd'] if 'wd' in elem.attributes else None
  
      return subprocess.run(command,
                            encoding='utf8',
                            stdout=subprocess.PIPE,
                            stderr=subprocess.STDOUT,
                            cwd=cwd).stdout
docs: Executes a code block by passing it to the executor.
  
      Args:
          elem The AST element.
          doc  The document.
  
      Returns:
          The output of the command.