extensions/references-view/src/utils.ts/WordAnchor/guessedTrackedPosition
class WordAnchor:	guessedTrackedPosition(): vscode.Position | undefined {
		// funky entry
		if (!this._word) {
			return this._position;
		}

		// no changes
		if (this._version === this._doc.version) {
			return this._position;
		}

		// no changes here...
		const wordNow = this._getAnchorWord(this._doc, this._position);
		if (this._word === wordNow) {
			return this._position;
		}

		// changes: search _word downwards and upwards
		const startLine = this._position.line;
		let i = 0;
		let line: number;
		let checked: boolean;
		do {
			checked = false;
			// nth line down
			line = startLine + i;
			if (line < this._doc.lineCount) {
				checked = true;
				const ch = this._doc.lineAt(line).text.indexOf(this._word);
				if (ch >= 0) {
					return new vscode.Position(line, ch);
				}
			}
			i += 1;
			// nth line up
			line = startLine - i;
			if (line >= 0) {
				checked = true;
				const ch = this._doc.lineAt(line).text.indexOf(this._word);
				if (ch >= 0) {
					return new vscode.Position(line, ch);
				}
			}
		} while (i < 100 && checked);

		// fallback
		return this._position;
	}