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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 update_command(args):
 """Updates all dependencies the specified requirements file."""

    updated = update_requirements_file(
        args.requirements_file, args.skip_packages)

    if updated:
        print('Updated requirements in {}:'.format(args.requirements_file))

        for item in updated:
            print(' * {} from {} to {}.'.format(*item))
    else:
        print('All dependencies in {} are up-to-date.'.format(
            args.requirements_file))