/**
* Updates the value of the field to a specified value if the specified value is less than the current value of the field.
*
* @see Expr::min()
* @see http://docs.mongodb.org/manual/reference/operator/update/min/
* @param mixed $value
* @return self
*/
public function min($value)
{
$this->expr->min($value);
return $this;
}