Generator: only process MathML element nodes.
Generator: only process MathML element nodes.

MichaelClerx/libcellml,cellml/libcellml,hsorby/libcellml,hsorby/libcellml,MichaelClerx/libcellml,hsorby/libcellml,nickerso/libcellml,nickerso/libcellml,nickerso/libcellml,cellml/libcellml,cellml/libcellml,MichaelClerx/libcellml,nickerso/libcellml,cellml/libcellml,hsorby/libcellml