public int compare(@Nullable String lhs, @Nullable String rhs) {
      if (lhs == rhs) {
        return 0;
      }
      if (lhs == null) {
        // lhs (null) comes just before justAfterNull.
        // If rhs is b, lhs comes first.
        if (rhs.equals(justAfterNull)) {
          return -1;
        }
        return justAfterNull.compareTo(rhs);
      }
      if (rhs == null) {

    public int compare(@Nullable String lhs, @Nullable String rhs) {
      if (lhs == rhs) {
        return 0;
      }
      if (lhs == null) {
        // lhs (null) comes just before justAfterNull.
        // If rhs is b, lhs comes first.
        if (rhs.equals(justAfterNull)) {
          return -1;
        }
        return justAfterNull.compareTo(rhs);
      }
      if (rhs == null) {

// expression.
type Initializer struct {
	Lhs []*Var // var Lhs = Rhs
	Rhs syntax.Expr
}

func (init *Initializer) String() string {
	var buf strings.Builder
	for i, lhs := range init.Lhs {
		if i > 0 {
			buf.WriteString(", ")
		}
		buf.WriteString(lhs.Name())
	}
	buf.WriteString(" = ")
	syntax.Fprint(&buf, init.Rhs, syntax.ShortForm)
	return buf.String()
}

    ): FirLiteralExpression? {
        if (value == null || other.value == null) return null
        // NB: some utils accept very general types, and due to the way operation map works, we should up-cast rhs type.
        val rightType = when {
            function.symbol.callableId.isStringEquals -> CompileTimeType.ANY
            function.symbol.callableId.isStringPlus -> CompileTimeType.ANY