How to make breadcrumbs_on_rails render a Bootstrap 4 compatible breadcrumb navigation

bootstrap_breadcrumbs_builder.rb

# The BootstrapBreadcrumbsBuilder is a Bootstrap compatible breadcrumb builder.
# It provides basic functionalities to render a breadcrumb navigation according to Bootstrap 4's conventions.
#
# You can use it with the :builder option on render_breadcrumbs:
#     <%= render_breadcrumbs builder: ::BootstrapBreadcrumbsBuilder %>
#
# Note: You may need to adjust the autoload_paths in your config/application.rb file for rails to load this class:
#     config.autoload_paths += %W(#{config.root}/lib)
#
class BootstrapBreadcrumbsBuilder < BreadcrumbsOnRails::Breadcrumbs::Builder
  def render
    @context.content_tag(:ul, class: 'breadcrumb') do
      @elements.collect do |element|
        render_element(element)
      end.join.html_safe
    end
  end

  def render_element(element)
    current = @context.current_page?(compute_path(element))

    @context.content_tag(:li, class: "breadcrumb-item #{'active' if current}") do
      @context.link_to_unless_current(compute_name(element), compute_path(element), element.options)
    end
  end
end