input: Write a function to generate a unique snowflake pattern by randomly selecting values and applying mathematical operations to create the coordinates of the snowflake. The function should take no parameters and return a list of three float values representing the coordinates of the snowflake.
  assert generate_snowflake() != generate_snowflake()
  assert len(generate_snowflake()) == 3
  assert all(isinstance(coord, float) for coord in generate_snowflake())
output: import random
  
  def generate_snowflake():
      x = random.uniform(-1, 1)
      y = random.uniform(-1, 1)
      z = random.uniform(-1, 1)
      return [x, y, z]