docstr: ...Test HawkesKernelExp latex string representation
          
code: def test_HawkesKernelExp_strtex(self):
      """...Test HawkesKernelExp latex string representation"""
      decay = 2
      intensity = 3
      hawkes_kernel_exp = HawkesKernelExp(intensity, decay)
      self.assertEqual(hawkes_kernel_exp.__strtex__(), "$6 e^{-2 t}$")
  
      intensity = 3
      decay = 0
      hawkes_kernel_exp = HawkesKernelExp(intensity, decay)
      self.assertEqual(hawkes_kernel_exp.__strtex__(), "$3$")
  
      intensity = 0
      decay = 2
      hawkes_kernel_exp = HawkesKernelExp(intensity, decay)
      self.assertEqual(hawkes_kernel_exp.__strtex__(), "$0$")
  
      intensity = 0.5
      decay = 2
      hawkes_kernel_exp = HawkesKernelExp(intensity, decay)
      self.assertEqual(hawkes_kernel_exp.__strtex__(), "$e^{-2 t}$")
  
      decay = 1
      intensity = 3
      hawkes_kernel_exp = HawkesKernelExp(intensity, decay)
      self.assertEqual(hawkes_kernel_exp.__strtex__(), "$3 e^{- t}$")
  
      decay = 1
      intensity = 1
      hawkes_kernel_exp = HawkesKernelExp(intensity, decay)
      self.assertEqual(hawkes_kernel_exp.__strtex__(), "$e^{-t}$")
  
file_path: tick/tick/hawkes/simulation/tests/hawkes_kernel_exp_test.py
imports: import unittest
  from tick.hawkes import HawkesKernelExp
label_desc: Use image node_id 6 for calling the Test obj's underlying member method code with example usage: obj.test_HawkesKernelExp_strtex() without return types