- https://git.eclipse.org/r/#/c/33800/3/bundles/org.eclipse.e4.tools.css.editor/src/org/eclipse/e4/CSS.xtext - https://github.com/dslmeinte/LessCss/blob/master/nl.dslmeinte.xtext.less/src/nl/dslmeinte/xtext/less/Less.xtext
