@Override
  public @NotNull DfType fromRelation(@NotNull RelationType relationType) {
    if (relationType == RelationType.EQ || relationType == RelationType.IS) {
      DfReferenceType result = this;
      if (myConstraint.isComparedByEquals()) {
        result = result.dropLocality();
      }
      if (myNullability == DfaNullability.NULLABLE) {
        result = result.dropNullability();
      }
      return result;
    }
    if (relationType == RelationType.IS_NOT) {
      DfType negated = tryNegate();
      if (negated != null) {
        return negated;
      }
    }
    return DfTypes.OBJECT_OR_NULL;
  }
@Override
  public @NotNull DfType fromRelation(@NotNull RelationType relationType)