lithium\data\Schema::is()
Detects properties of a field, i.e. if it supports arrays.
Parameters
- 
							string
							
$condition - 
							string
							
$field 
Returns
booleanSource
	public function is($condition, $field) {
		if (!isset($this->_fields[$field])) {
			return null;
		}
		return isset($this->_fields[$field][$condition]) && $this->_fields[$field][$condition];
	}