Classes/Console/Service/XsdGenerator.php
protected function getTagNameForClass($className)
    {
        /// Strip namespace from the beginning and "ViewHelper" from the end of the class name
        $strippedClassName = substr($className, strpos($className, 'ViewHelpers') + 12, -10);
        $classNameParts = explode('\\', $strippedClassName);

        return implode(
            '.',
            array_map(
                function ($element) {
                    return lcfirst($element);
                },
                $classNameParts
            )
        );
    }
protected function getTagNameForClass($className)
    {
        /// Strip namespace from the beginning and "ViewHelper" from the end of the class name
        $strippedClassName = substr($className, strpos($className, 'ViewHelpers') + 12, -10);
        $classNameParts = explode('\\', $strippedClassName);

        return implode(
            '.',
            array_map(
                function ($element) {
                    return lcfirst($element);
                },
                $classNameParts
            )
        );
    }
Get a tag name for a given ViewHelper class.
Example: For the View Helper TYPO3\CMS\Fluid\ViewHelpers\Form\SelectViewHelper, and the
namespace prefix TYPO3\CMS\Fluid\ViewHelpers\, this method returns "form.select".

@param string $className Class name
@return string Tag name