code: def y_exact(self, t):
      return self.a * t + self.b
  
file_path: torchdiffeq/tests/problems.py
imports: import math
  import numpy
  import scipy.linalg
  import torch
label_desc: Use image node_id 3 for calling the ConstantODE obj's underlying member method code with example usage: obj.y_exact(t) and returns: unknown