@staticmethod
def drop_hostname(email):
    """
        >>> Context.drop_hostname("foo")
        'foo'
        >>> Context.drop_hostname("foo@bar.com")
        'foo'
        >>> Context.drop_hostname("")
        ''
        >>> Context.drop_hostname("@")
        ''
        """
    try:
        n = email.index('@')
    except ValueError:
        return email
    else:
        return email[0:n]
