# File htree/context.rb, line 18
    def initialize(namespaces=nil)
      namespaces ||= DefaultNamespaces
      namespaces.each_pair {|k, v|
        check_namespace_prefix(k)
        check_namespace_uri(v)
      }
      namespaces = namespaces.dup.freeze unless namespaces.frozen?
      @namespaces = namespaces
    end