code: def unionRect(rect1, rect2):
      """Determine union of bounding rectangles.
  
      Args:
          rect1: First bounding rectangle, expressed as tuples
              ``(xMin, yMin, xMax, yMax)``.
          rect2: Second bounding rectangle.
  
      Returns:
          The smallest rectangle in which both input rectangles are fully
          enclosed.
      """
      (xMin1, yMin1, xMax1, yMax1) = rect1
      (xMin2, yMin2, xMax2, yMax2) = rect2
      xMin, yMin, xMax, yMax = (
          min(xMin1, xMin2),
          min(yMin1, yMin2),
          max(xMax1, xMax2),
          max(yMax1, yMax2),
      )
      return (xMin, yMin, xMax, yMax)
  
imports: from fontTools.misc.roundTools import otRound
  from fontTools.misc.vector import Vector
  import math
  import warnings
label_desc: Use image node_id 13 for calling a global function with example usage: unionRect(rect1, rect2) and returns: xMin,  yMin,  xMax,  yMax