old_contents: #!/usr/bin/env python
  
  from nodes import Node
  import math
  
  class FloorDiv(Node):
      char = "f"
      args = 2
      results = 1
      
      @Node.test_func([3,2], [1])
      @Node.test_func([6,-3], [-2])
      def func(self, a:Node.number,b:Node.number):
          """a/b. Rounds down, returns an int."""
          return a//b
      
      @Node.test_func(["test", "e"], [["t", "e", "st"]])
      def partition(self, string:str, sep:str):
          """Split the string at the first occurrence of sep,
  return a 3-list containing the part before the separator,
  the separator itself, and the part after the separator.
  If the separator is not found,
  return a 3-list containing the string itself,
  followed by two empty strings."""
          return [list(string.partition(sep))]
      
      @Node.test_func(["134", 1], [["134"]])
      @Node.test_func(["1234", 2], [["12", "34"]])
      @Node.test_func(["1234", 3], [["1", "2", "34"]])
      @Node.test_func([[4,8,15,16,23,42], 5], [[[4],[8],[15],[16],[23,42]]])
      @Node.test_func(["123456789", 5], [['1', '2', '3', '4', '56789']])
      @Node.test_func([[4,8,15,16,23,42], 7], [[[],[],[],[],[],[],[4,8,15,16,23,42]]])
      def chunk(self, inp:Node.indexable, num:int):
          """Return inp seperated into num groups"""
          rtn = []
          size = len(inp)//num
          try:
              for i in range(0, num*size, size):
                  rtn.append(inp[i:i+size])
          except ValueError:
              for i in range(num): rtn.append([])
              i = 0
          if len(rtn) != num:
              rtn.append(inp[i+size:])
          else:
              rtn[-1] += inp[i+size:]
          return [rtn]
      
      @Node.test_func([[4, 4, 2, 2, 9, 9], [0, -2, 0, 7, 0]], [[[4,4],[2,2],[9,9]]])
      def split_at(self, inp:Node.sequence, splits:Node.sequence):
          """Split inp at truthy values in splits"""
          rtn = [[]]
          for i, do_split in zip(inp, splits+[0]):
              if do_split: rtn.append([])
              rtn[-1].append(i)
          return [rtn]
new_contents: #!/usr/bin/env python
  
  from nodes import Node
  import math
  
  class FloorDiv(Node):
      char = "f"
      args = 2
      results = 1
      
      @Node.test_func([3,2], [1])
      @Node.test_func([6,-3], [-2])
      def func(self, a:Node.number,b:Node.number):
          """a/b. Rounds down, returns an int."""
          return a//b
      
      @Node.test_func(["test", "e"], [["t", "e", "st"]])
      def partition(self, string:str, sep:str):
          """Split the string at the first occurrence of sep,
  return a 3-list containing the part before the separator,
  the separator itself, and the part after the separator.
  If the separator is not found,
  return a 3-list containing the string itself,
  followed by two empty strings."""
          return [list(string.partition(sep))]
      
      @Node.test_func(["134", 1], [["134"]])
      @Node.test_func(["1234", 2], [["12", "34"]])
      @Node.test_func(["1234", 3], [["1", "2", "34"]])
      @Node.test_func([[4,8,15,16,23,42], 5], [[[4],[8],[15],[16],[23,42]]])
      @Node.test_func(["123456789", 5], [['1', '2', '3', '4', '56789']])
      @Node.test_func([[4,8,15,16,23,42], 7], [[[],[],[],[],[],[],[4,8,15,16,23,42]]])
      def chunk(self, inp:Node.indexable, num:int):
          """Return inp seperated into num groups"""
          rtn = []
          size = len(inp)//num
          try:
              for i in range(0, num*size, size):
                  rtn.append(inp[i:i+size])
          except ValueError:
              for i in range(num): rtn.append([])
              i = 0
          if len(rtn) != num:
              rtn.append(inp[i+size:])
          else:
              rtn[-1] += inp[i+size:]
          return [rtn]
      
      @Node.test_func([[4, 4, 2, 2, 9, 9], [0, -2, 0, 7, 0]], [[[4],[4,2],[2,9,9]]])
      def split_at(self, inp:Node.sequence, splits:Node.sequence):
          """Split inp at truthy values in splits"""
          rtn = [[]]
          for i, do_split in zip(inp, splits+[0]):
              if do_split: rtn.append([])
              rtn[-1].append(i)
          return [rtn]
subject: Fix test cases