class T::Private::Methods::DeclBuilder

proc, because this is valid and would lead to a false positive: `T.type_alias { T.proc.params(a: Integer).void }`
Verify if we're trying to invoke the method outside of a signature block. Notice that we need to check if it's a

def check_running_inside_block!(method_name)
 @inside_sig_block || decl.mod == T::Private::Methods::PROC_TYPE
e BuilderError.new(
an't invoke #{method_name} outside of a signature declaration block"