text: class Solution:
      def merge(self, intervals: List[List[int]]) -> List[List[int]]:
          intervals = sorted(intervals, key = lambda x: x[0])
          i = 0
          while i < len(intervals) - 1:
              if intervals[i][1] >= intervals[i+1][0]:
                  intervals[i][1] = max(intervals[i][1], intervals[i+1][1])
                  del intervals[i+1]
              else:
                  i += 1
          return intervals