XML::Checker ERROR-101: undefined ELEMENT [a]
	Context: line 9, column 2, byte 176
XML::Checker ERROR-101: undefined ELEMENT [b]
	Context: line 10, column 2, byte 188
XML::Checker ERROR-153: Element should be EMPTY, found text [
]
	Context: line 12, column 4, byte 208
XML::Checker ERROR-153: Element should be EMPTY, found text [ ]
	Context: line 13, column 0, byte 209