src/Element/Username.php
public function getInputSpecification()
    {
        return [
            'name'       => $this->getName(),
            'required'   => true,
            'filters'    => [
                Filter\StringTrim::class    => [
                    'name' => Filter\StringTrim::class
                ],
                Filter\StripNewlines::class => [
                    'name' => Filter\StripNewlines::class
                ]
            ],
            'validators' => [
                UsernameValidator::class => [
                    'name' => UsernameValidator::class
                ]
            ]
        ];
    }
public function getInputSpecification()
    {
        return [
            'name'       => $this->getName(),
            'required'   => true,
            'filters'    => [
                Filter\StringTrim::class    => [
                    'name' => Filter\StringTrim::class
                ],
                Filter\StripNewlines::class => [
                    'name' => Filter\StripNewlines::class
                ]
            ],
            'validators' => [
                UsernameValidator::class => [
                    'name' => UsernameValidator::class
                ]
            ]
        ];
    }
Provide default input rules for this element and attaches an password validator.

@return array