src/Bootstrap/Elements/ControlWrapper.php
public function getAttribute($attribute, $fallback = null)
    {
        if (\in_array($attribute, $this->delegatedControlAttributes, true))
        {
            return $this->getControlAttribute($attribute, $fallback);
        }

        return parent::getAttribute($attribute, $fallback);
    }
public function getAttribute($attribute, $fallback = null)
    {
        if (\in_array($attribute, $this->delegatedControlAttributes, true))
        {
            return $this->getControlAttribute($attribute, $fallback);
        }

        return parent::getAttribute($attribute, $fallback);
    }
For some attributes, return the value of the backing control instead of our own

@param string $attribute
@param null   $fallback

@return mixed