'Resolve the specified prefix to a known namespace.
@param prefix: A declared prefix
@type prefix: basestring
@return: The namespace that has been mapped to I{prefix}
@rtype: (I{prefix}, I{name})'

def resolvePrefix(self, prefix):

    ns = Namespace.default
    if (self.parent is not None):
        ns = self.parent.resolvePrefix(prefix)
    return ns
