public function group($group, $context) {
		if (!$group) {
			return null;
		}
		$self = $this;
		$model = $context->model();
		$alias = $context->alias();

		$escaped = array_map(function($field) use ($self, $model, $alias) {
			if (!$model || !$model::schema($field)) {
				return $self->name($field);
			}
			return $self->name($alias) . '.' . $self->name($field);
		}, (array) $group);

		return 'GROUP BY ' .  join(', ', $escaped);
	}
public function group($group, $context) {
		if (!$group) {
			return null;
		}
		$self = $this;
		$model = $context->model();
		$alias = $context->alias();

		$escaped = array_map(function($field) use ($self, $model, $alias) {
			if (!$model || !$model::schema($field)) {
				return $self->name($field);
			}
			return $self->name($alias) . '.' . $self->name($field);
		}, (array) $group);

		return 'GROUP BY ' .  join(', ', $escaped);
	}
public function group ( $ group , $ context ) { if ( ! $ group ) { return null ; } $ self = $ this ; $ model = $ context -> model ( ) ; $ alias = $ context -> alias ( ) ; $ escaped = array_map ( function ( $ field ) use ( $ self , $ model , $ alias ) { if ( ! $ model || ! $ model :: schema ( $ field ) ) { return $ self -> name ( $ field ) ; } return $ self -> name ( $ alias ) . '.' . $ self -> name ( $ field ) ; } , ( array ) $ group ) ; return 'GROUP BY ' . join ( ', ' , $ escaped ) ; }
Return formatted clause for `GROUP BY` with known fields escaped.

@param string|array $group The clause to be formatted.
@param object $context
@return string|null Formatted clause, `null` if there is nothing to format.
Return formatted clause for GROUP BY with known fields escaped .