addFunInterface
inline fun TypeSpecHolder.Builder<*>.addFunInterface(name: String, block: TypeSpecBuilderScope = {}): TypeSpec(source)
inline fun TypeSpecHolder.Builder<*>.addFunInterface(className: ClassName, block: TypeSpecBuilderScope = {}): TypeSpec(source)
inline fun <C> TypeSpecHolder.Builder<*>.addFunInterface(block: TypeSpecBuilderScope = {}): TypeSpec(source)