code: def double_exp(x, a1, t1, a2, t2):
      return a1 * np.exp(-x / t1) + a2 * np.exp(-(x - 0.1) / t2)
  
imports: import corner
  import matplotlib.pyplot
  import numpy
  import lmfit
label_desc: Use image node_id 1 for calling a global function with example usage: double_exp(x, a1, t1, a2, t2) and returns: unknown