code: def calculate_pair_sum(arr):
      if len(arr) == 1:
          return list(arr)
      else:
          res = [arr[i] + arr[i + 1] for i in range(0, len(arr) - 1, 2)]
          if len(arr) % 2 == 1:
              res.append(arr[-2] + arr[-1])
          return res
  
imports: import numpy
label_desc: Use image node_id 5 for calling a global function with example usage: calculate_pair_sum(arr) and returns: list, res