module EacRubyUtils::ActsAsAbstract::ClassMethods

def abstract_methods(*methods_names)
  methods_names.each do |method_name|
    if method_name.is_a?(::Hash)
      abstract_methods_from_hash(method_name)
    else
      abstract_method(method_name)
    end
  end
end

def abstract_methods_from_hash(hash)
  hash.each { |name, arguments| abstract_method(name, *arguments) }
end

def abstract_methods_hash
  @abstract_methods_hash ||=
    ::EacRubyUtils::ModuleAncestorsVariable::Hash.new(self, __method__)
end