code: def find_closing_braces(self, query):
      
      if query[0] != '(':
        raise Exception("Trying to find closing braces for no opening braces")
      num_open_braces = 0
      for i in range(len(query)):
        c = query[i]
        if c == '(':
          num_open_braces += 1
        elif c == ')':
          num_open_braces -= 1
        if num_open_braces == 0:
          return i
      raise Exception("No closing braces found")
docs: Find the index of the closing braces for the opening braces
      at the start of the query string. Note that first character
      of input string must be an opening braces.