code: protected function getArrayConditionSep($dataMember, $statementNum, $offset)
      {
          if (isset($this->{$dataMember}[$statementNum][0][$offset][3])) {
              return ' '.$this->{$dataMember}[$statementNum][0][$offset][3].' ';
          }
          return false;
      }
docs: If the optional 4th array parameter denoting the desired conjunction for the next condition is set
  within a condition statement, then return that separator.
  E.g. the 'OR' below:
  [
  ['id', '>', '100', 'OR'],
  ['name', 'LIKE', '%s']
  ]