class RBS::NoMixinFoundError

def self.check!(type_name, env:, member:)

def self.check!(type_name, env:, member:)
  (env.module_name?(type_name) || env.interface_name?(type_name)) or raise new(type_name: type_name, member: member)
end

def initialize(type_name:, member:)

def initialize(type_name:, member:)
  @type_name = type_name
  @member = member
  super "#{Location.to_string location}: Could not find mixin: #{type_name}"
end

def location

def location
  member.location
end