def empty_nil_blank?(str, raize=false)
      result = (str !~ /[^[:space:]]/ || str.nil? || str.empty?)
      raise ShellTastic::CommandException.new("Command is emtpy or nil") if result and raize
      result
    end
def empty_nil_blank?(str, raize=false)
      result = (str !~ /[^[:space:]]/ || str.nil? || str.empty?)
      raise ShellTastic::CommandException.new("Command is emtpy or nil") if result and raize
      result
    end
like the other methods but allow to set an exception flag
 @param  [String] str the string the needs to be checked
 @param  [Boolean] to raise an exception or not. DEFAULT is false
 @return [Boolean]
 @return [ShellTastic::CommandException]