"""Executes a shell command and returns the std out and std error.

[copybara-service]

"""Executes a shell command and returns the std out and std error.

Args:
  command: List or string representing the command to run.
  env: Dictionary of environment variable settings. If None, no environment
    variables will be set for the child process. This is to make tests more
    hermetic. NOTE: this behavior is different than the standard subprocess
    module.
  close_fds: Whether or not to close all open fd's in the child after
    forking.

Returns:
  A tuple of (return code, std error).
"""