code: public boolean alreadyPresent(ImportedKey importedKey) {
          if (foreignKeysByName == null) {
              return false;
          }
  
          Collection<ForeignKey> fks = foreignKeysByName.values();
          if (fks == null) {
              return false;
          }
  
          for (ForeignKey fk : fks) {
              if (fk.getSize() == 1) {
                  ImportedKey other = fk.getImportedKey();
                  // Note: we just need to compare the FkColumnName, if we have a match, we consider
                  // that this is an error in the conf, and we skip. No need to compare pkTable and pkCol
                  boolean same = importedKey.getFkColumnName().equalsIgnoreCase(other.getFkColumnName());
  
                  if (same) {
                      return true;
                  }
              }
          }
          return false;
      }
docs: /*
  Check if the passed importedKey is already present or not in a existing ForeignKey of size 1.