code: def test_scan(self):
      code = """
  def prefix(A): return scan(lambda x,y:x+y, A)
  def scan(f, A):
      B = list(A)
      for i in range(1, len(B)):
          B[i] = f(B[i-1], B[i])
      return B
  """
      self.run_test(code, [1.0, 2.0, 3.0], prefix=[List[float]])
  
imports: from pythran.tests import TestEnv
  from pythran.typing import *
label_desc: Use image node_id 15 for calling the TestCopperhead obj's underlying member method code with example usage: obj.test_scan() without return types