code: def trySwitchStatement(self, block):
          
          if not re.match(r'^\s*(default\s*|case\b.*):', block.text()):
              return None
  
          for block in self.iterateBlocksBackFrom(block.previous()):
              text = block.text()
              if re.match(r"^\s*(default\s*|case\b.*):", text):
                  dbg("trySwitchStatement: success in line %d" % block.blockNumber())
                  return self._lineIndent(text)
              elif re.match(r"^\s*switch\b", text):
                  if CFG_INDENT_CASE:
                      return self._increaseIndent(self._lineIndent(text))
                  else:
                      return self._lineIndent(text)
  
          return None
docs: Check for default and case keywords and assume we are in a switch statement.
          Try to find a previous default, case or switch and return its indentation or
          None if not found.