code: function first_in_statement(stack) {
        var node = stack.parent(-1);
        for (var i = 0, p; p = stack.parent(i); i++) {
            if (p instanceof AST_Statement && p.body === node)
                return true;
            if ((p instanceof AST_Sequence      && p.expressions[0] === node) ||
                (p.TYPE == "Call"               && p.expression === node ) ||
                (p instanceof AST_Dot           && p.expression === node ) ||
                (p instanceof AST_Sub           && p.expression === node ) ||
                (p instanceof AST_Conditional   && p.condition === node  ) ||
                (p instanceof AST_Binary        && p.left === node       ) ||
                (p instanceof AST_UnaryPostfix  && p.expression === node )
            ) {
                node = p;
            } else {
                return false;
            }
        }
    }
docs: return true if the node at the top of the stack (that means the innermost node in the current output) is lexically the first in a statement.