def call(event)
      each do |filter|
        result = filter.call(event)
        return false if result == false
      end
      event
    end
def call(event)
      each do |filter|
        result = filter.call(event)
        return false if result == false
      end
      event
    end
Filter the given event by calling each defined filter with it. Each filter
 will be called with the current event and can manipulate it in any way.

 If any of the filters returns `false`, no further filter will be applied
 and we also return `false`. This behavior can be used by filters to cancel
 the writing of an individual event. Any other return value of filters is
 ignored.

 @param event [Hash] an event hash, see {Buffer#event} for details
 @return [Hash, false] the filtered event or `false` if any of the
   filters returned `false`