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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 did_composer_install(dir):
    '''
    Test to see if the vendor directory exists in this directory

    dir
        Directory location of the composer.json file

    CLI Example:

    .. code-block:: bash

        salt '*' composer.did_composer_install /var/www/application
    '''
    lockFile = "{0}/vendor".format(dir)
    if os.path.exists(lockFile):
        return True
    return False