code: def _get_fmt(self, fmt):
          
  
          # iterate over the format string looking for format specifiers
          components = [ ]
          i = 0
          while i < len(fmt):
              if type(fmt[i]) is bytes and fmt[i] == b"%":
                  # Note that we only support concrete format specifiers
                  # grab the specifier
                  # go to the space
                  specifier = b""
                  for c in fmt[i+1:]:
                      if type(c) is bytes:
                          specifier += c
                      else:
                          break
  
                  specifier = self._match_spec(specifier)
                  if specifier is not None:
                      i += len(specifier)
                      components.append(specifier)
                  else:
                      # if we get here we didn't match any specs, the first char will be thrown away
                      # and we'll add the percent
                      i += 1
                      components.append(b'%')
              else:
                  # claripy ASTs, which are usually symbolic variables
                  # They will be kept as they are - even if those chars can be evaluated to "%"
                  components.append(fmt[i])
              i += 1
  
          return FormatString(self, components)
docs: Extract the actual formats from the format string `fmt`.
  
          :param list fmt: A list of format chars.
          :returns: a FormatString object