code: public boolean assertValidPksForStore(FieldDescriptor[] fieldDescriptors, Object[] pkValues)
      {
          int fieldDescriptorSize = fieldDescriptors.length;
          for(int i = 0; i < fieldDescriptorSize; i++)
          {
              FieldDescriptor fld = fieldDescriptors[i];
              /**
               * a pk field is valid if it is either managed by OJB
               * (autoincrement or locking) or if it does contain a
               * valid non-null value.
               */
              if(!(fld.isAutoIncrement()
                      || fld.isLocking()
                      || !representsNull(fld, pkValues[i])))
              {
                  return false;
              }
          }
          return true;
      }
docs: returns true if the primary key fields are valid for store, else false.
  PK fields are valid if each of them is either an OJB managed
  attribute (autoincrement or locking) or if it contains
  a valid non-null value
  @param fieldDescriptors the array of PK fielddescriptors
  @param pkValues the array of PK values
  @return boolean