code: def varargs_func_fixture():
      """
      Register a varargs scalar function with at least two arguments.
      """
  
      def varargs_function(ctx, first, *values):
          acc = first
          for val in values:
              acc = pc.call_function(
                  "add", [acc, val], memory_pool=ctx.memory_pool
              )
          return acc
  
      func_name = "z=ax+by+c"
      varargs_doc = {
          "summary": "z=ax+by+c",
          "description": "find z from z = ax + by + c",
      }
      pc.register_scalar_function(
          varargs_function,
          func_name,
          varargs_doc,
          {
              "array1": pa.int64(),
              "array2": pa.int64(),
          },
          pa.int64(),
      )
      return varargs_function, func_name
  
imports: import pytest
  import numpy
  import pyarrow
  from pyarrow import compute
label_desc: Use image node_id 8 for calling a global function with example usage: varargs_func_fixture() and returns: varargs_function,  func_name, acc