code: public String getAttributeId(int variableId) throws MIDDParsingException {
          if (!attributeMapper.containsValue(variableId)) {
              throw new MIDDParsingException("Variable identifier '" + variableId + "' not found");
          }
  
          for (String attrId : attributeMapper.keySet()) {
              if (attributeMapper.get(attrId) == variableId) {
                  return attrId;
              }
          }
  
          throw new MIDDParsingException("Variable identifier '" + variableId + "' not found");
      }
docs: Return the attribute identifier from the variable-id
  
  @param variableId
  @return
  @throws MIDDParsingException