presto-parser/src/main/java/io/prestosql/sql/tree/NodeRef.java/NodeRef/equals
class NodeRef:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        NodeRef<?> other = (NodeRef<?>) o;
        return node == other.node;
    }