class SimpleForm::Inputs::CollectionRadioButtonsInput

def apply_default_collection_options!(options) 

def apply_default_collection_options!(options)
  options[:item_wrapper_tag] ||= options.fetch(:item_wrapper_tag, SimpleForm.item_wrapper_tag)
  options[:item_wrapper_class] = [
    item_wrapper_class, options[:item_wrapper_class], SimpleForm.item_wrapper_class
  ].compact.presence
  options[:collection_wrapper_tag] ||= options.fetch(:collection_wrapper_tag, SimpleForm.collection_wrapper_tag)
  options[:collection_wrapper_class] = [
    options[:collection_wrapper_class], SimpleForm.collection_wrapper_class
  ].compact.presence
end

def apply_nested_boolean_collection_options!(options)

compatibility with :inline style and default :item_wrapper_tag.
configuring classes through :item_wrapper_class, and to maintain
Force item wrapper to be a label when using nested boolean, to support 
def apply_nested_boolean_collection_options!(options)
  options[:item_wrapper_tag] = :label
end

def build_nested_boolean_style_item_tag(collection_builder) 

def build_nested_boolean_style_item_tag(collection_builder)
  collection_builder.radio_button + collection_builder.text
end

def collection_block_for_nested_boolean_style 

def collection_block_for_nested_boolean_style
  return unless nested_boolean_style?
  proc { |builder| build_nested_boolean_style_item_tag(builder) }
end

def generate_label_for_attribute?

non existent fields.
explicit html option is given. This avoids generating labels pointing to
Do not attempt to generate label[for] attributes by default, unless an 
def generate_label_for_attribute?
  false
end

def input 

def input
  label_method, value_method = detect_collection_methods
  @builder.send("collection_#{input_type}",
    attribute_name, collection, value_method, label_method,
    input_options, input_html_options, &collection_block_for_nested_boolean_style
  )
end

def input_options 

def input_options
  options = super
  apply_default_collection_options!(options)
  apply_nested_boolean_collection_options!(options) if nested_boolean_style?
  options
end

def item_wrapper_class 

def item_wrapper_class
  "radio"
end