src/vs/editor/contrib/wordHighlighter/wordHighlighter.ts/WordHighlighter/_getWord
class WordHighlighter:	private _getWord(): IWordAtPosition | null {
		let editorSelection = this.editor.getSelection();
		let lineNumber = editorSelection.startLineNumber;
		let startColumn = editorSelection.startColumn;

		return this.model.getWordAtPosition({
			lineNumber: lineNumber,
			column: startColumn
		});
	}