code: function(body, errorMessage) {
        var dsl = this.DSL || this.DSLs.snake
        var matchers = this.matchers
        var context = this.context || this.defaultContext
        var contents = this.contentsOf(body)
        hook('evaluatingBody', dsl, matchers, context, contents)
        try { with (dsl){ with (context) { with (matchers) { eval(contents) }}} }
        catch(e) { error(errorMessage, e) }
      }
docs: Evaluate a JSpec capture body.
  
  @param  {function} body
  @param  {string} errorMessage (optional)
  @return {Type}
  @api private