The raw content of the mixin body, to be expanded when included. This includes nested rules which will be parsed during expansion.

Source line for error messages

Source file for error messages

Whether this mixin has a variadic parameter (last param ends with ...)

The name of the mixin (e.g., "button" from "@mixin button")

Parameter definitions in order, with optional default values. Key = parameter name (without $), Value = default value (null if required)