This is a built-in template used for filling the initializer of a Kotlin property each time it is generated by the program, e.g. when using the Create Property from Usage intention action.
The template is editable. Along with Kotlin expressions and comments, you can also use the predefined variables that will be then expanded into the corresponding values.
Predefined variables will take the following values:
${RETURN_TYPE}   a type of a created property
${PROPERTY_NAME}   name of the created property
${CLASS_NAME}   qualified name of the class where property is created
${SIMPLE_CLASS_NAME}   non-qualified name of the class where property is created