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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def execute_command(command=None):
 """Execute a command and return the stdout and stderr."""

    process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout, stdin = process.communicate()
    process.wait()
    return (stdout, stdin), process.returncode