# File rbSnack/tkSnack.rb, line 456
    def crop( startPos=1, endPos=nil, options=nil, &op_block) 
        options=SnOp::makeOps(options, &op_block)
        endPos = length if endPos==nil      
        Snack::exeTkCmd([@name, 'crop', startPos, endPos], options)
    end