The latest version of web-facelettaglibrary_2_0.xsd that ships with Mojarra defines a <method-
signature> element that is used to specify the method signature for MethodExpression attributes.
However, the online version of the XSD here:
Does not include this element. I believe that this is an oversight. FWIW, the spec does allow this
element to be defined in composite component metadata (see Appendix A, section 1.4).
Note that Trinidad is leveraging method-signature elements in order to improve our DT experience,
but we are running into validation errors when validating against the XSD on java.sun.com. See: