new

# File activesupport/lib/active_support/callbacks.rb, line 298
        def initialize(name, filter, kind, options, chain_config)
          @chain_config = chain_config
          @name    = name
          @kind    = kind
          @filter  = filter
          @key     = compute_identifier filter
          @if      = check_conditionals(Array(options[:if]))
          @unless  = check_conditionals(Array(options[:unless]))
        end