public boolean isEqualityComparison(Class<?>... types) {
    if (!isEqualityComparison()) return false;
    if (!ReflectionUtil.hasAnyOfTypes(children.get(0).getValue(), types)) return false;
    if (!ReflectionUtil.hasAnyOfTypes(children.get(1).getValue(), types)) return false;
    return true;
  }
Examples where operation is null:
- GString method name: foo."$bar"()
- Argument list (has children but no operation)
spock-core/src/main/java/org/spockframework/runtime/model/ExpressionInfo.java