code: def run(command, input=None, exit=0, shell=False):
          
          if isinstance(input, str):
              input = input.encode()
  
          # Only pipe stdin if we have input to pipe.
          stdin = {} if input is None else {"stdin": subprocess.PIPE}
          try:
              child = subprocess.Popen(command, stdout=subprocess.PIPE,
                                       stderr=subprocess.PIPE, **stdin)
          except FileNotFoundError as e:
              # Extract name of command.
              name = command.split(' ', 1)[0] if isinstance(command, str) else command[0]
              raise DependencyError(name)
  
          stdout, _ = child.communicate(input=input)
          if exit is not None and child.returncode != exit:
              raise Error("failed to stylecheck code")
          return stdout.decode()
docs: Run `command` passing it stdin from `input`, throwing a DependencyError if comand is not found.
          Throws Error if exit code of command is not `exit` (unless `exit` is None).