def modify_for_endianness(str, use_case = false)
      case [tags[:endian], use_case]
      when [:little, true]
        str.swapcase
      when [:little, false]
        str + "<"
      when [:big, true]
        str
      when [:big, false]
        str + ">"
      else
        str
      end
    end
def modify_for_endianness(str, use_case = false)
      case [tags[:endian], use_case]
      when [:little, true]
        str.swapcase
      when [:little, false]
        str + "<"
      when [:big, true]
        str
      when [:big, false]
        str + ">"
      else
        str
      end
    end
Modifies the given string to account for endianness.  If
 +use_case+ is true, it modifies the case of the given string to
 represent endianness; otherwise, it appends data to the string
 to represent endianness.

 @param str [String] the string to modify.
 @param use_case [Boolean]
 @return [String]