'Return a child parameter.
Accepts the name of the child or a tuple (path, to, child)
Added in version 0.9.9. Ealier versions used the \'param\' method, which is still
implemented for backward compatibility.'

def child(self, *names):

    try:
        param = self.names[names[0]]
    except KeyError:
        raise Exception(('Parameter    %s    has    no    child    named    %s' % (self.name(), names[0])))
    if (len(names) > 1):
        return param.param(*names[1:])
    else:
        return param
