Write a function to find the volume of a cone.
import math
def volume_cone(r,h):
  volume = (1.0/3) * math.pi * r * r * h
  return volume
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to find the volume of a cone.
import math
def volume_cone(r,h):
  volume = (1.0/3) * math.pi * r * r * h
  return volume[/INST]assert volume_cone(5,12)==314.15926535897927
assert volume_cone(10,15)==1570.7963267948965
assert volume_cone(19,17)==6426.651371693521</s>