code: def sphere_increasing(middle, pos):
      return sqrt(1.0 - (linear(middle, pos) - 1.0) ** 2)
  
file_path: pillow/src/PIL/GimpGradientFile.py
imports: from __future__ import annotations
  from math import log, pi, sin, sqrt
  from ._binary import o8
label_desc: Use image node_id 4 for calling a global function with example usage: sphere_increasing(middle, pos) and returns: sqrt