def render_file(file, locs, opts, &block)
      _render_with_all_renderers(file[:relative_path].to_s, locs, self, opts, &block)
    end
def render_file(file, locs, opts, &block)
      _render_with_all_renderers(file[:relative_path].to_s, locs, self, opts, &block)
    end
Render a path with locs, opts and contents block.

 @api private
 @param [Middleman::SourceFile] file The file.
 @param [Hash] locs Template locals.
 @param [Hash] opts Template options.
 @param [Proc] block A block will be evaluated to return internal contents.
 @return [String] The resulting content string.
 Contract IsA['Middleman::SourceFile'], Hash, Hash, Maybe[Proc] => String