'@type key: bytes
@param key: The key to test
@return: A true value if this dirdbm has the specified key, a false
value otherwise.'

def has_key(self, key):

    if (not (type(key) == bytes)):
        raise TypeError('DirDBM    key    must    be    bytes')
    key = self._encode(key)
    return self._dnamePath.child(key).isfile()
