def left(*conditions, &effect)
      branch = Fear.case(Fear::Left, &LEFT_EXTRACTOR).and_then(Fear.case(*conditions, &effect))
      or_else(branch)
    end
def left(*conditions, &effect)
      branch = Fear.case(Fear::Left, &LEFT_EXTRACTOR).and_then(Fear.case(*conditions, &effect))
      or_else(branch)
    end
Match against +Fear::Left+

 @param conditions [<#==>]
 @return [Fear::EitherPatternMatch]