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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 get(key, default=''):
    '''
    Get a single salt process environment variable.

    key
        String used as the key for environment lookup.

    default
        If the key is not found in the environment, return this value.
        Default: ''


    CLI Example:

    .. code-block:: bash

        salt '*' environ.get foo
        salt '*' environ.get baz default=False
    '''
    if not isinstance(key, six.string_types):
        log.debug('%s: \'key\' argument is not a string type: \'%s\'', __name__, key)
        return False
    return os.environ.get(key, default)