code: function equalDiff(a, b, diff) {
    diff.a = {
      line: a.line,
      column: a.column
    };
    diff.b = {
      line: b.line,
      column: b.column
    };
    return false;
  }
docs: /*
  Fills a diff object with line and column of unmatching nodes.
  @param {AstNode} a Example node.
  @param {AstNode} b Node that should have a's properties.