# File test/core_test.rb, line 254
 def test_parent
		parent = Parent.new
		begin
			parent << "Something"
		rescue
			parent << Comment.new("Some comment")
			assert parent.size == 1, "size of parent should be 1"
		else
			assert_fail "should have gotten an exception trying to add a "+ "String to a Parent"
		end

		source = "<a><one/><three/><five/></a>"
		doc = Document.new source
		three = doc.root.elements["three"]
		doc.root.insert_before( three, Element.new("two") )
		nxt = doc.root.elements["one"]
		string = ""
		while nxt
			string << nxt.name
			nxt = nxt.next_sibling
		end
		assert_equal "onetwothreefive", string


		doc.root.insert_after( three, Element.new("four") )
		string = ""
		doc.root.each { |element| string << element.name }
		assert_equal "onetwothreefourfive", string

		string = ""
		nxt = doc.root.elements["five"]
		while nxt
			string << nxt.name
			nxt = nxt.previous_sibling
		end
		assert_equal "fivefourthreetwoone", string

		doc.insert_after "//two", Element.new("two-and-half")
		string = doc.root.elements.collect {|x| x.name}.join
		assert_equal "onetwotwo-and-halfthreefourfive", string
		doc.elements["/a/five"].insert_before "../four", Element.new("three-and-half")
		string = doc.root.elements.collect {|x| x.name}.join
		assert_equal "onetwotwo-and-halfthreethree-and-halffourfive", string

		doc.elements["/a/five"].previous_sibling = Element.new("four-and-half")
		string = doc.root.elements.collect {|x| x.name}.join
		assert_equal "onetwotwo-and-halfthreethree-and-halffourfour-and-halffive", string
		doc.elements["/a/one"].next_sibling = Element.new("one-and-half")
		string = doc.root.elements.collect {|x| x.name}.join
		assert_equal "oneone-and-halftwotwo-and-halfthreethree-and-halffourfour-and-halffive", string

		doc = Document.new "<a><one/><three/></a>"
		doc.root[1,0] = Element.new "two"
		string = ""
		doc.root.each { |el| string << el.name }
		assert_equal "onetwothree", string
	end