code: def flat_outer(a, b):
      return pt.outer(a, b).ravel()
  
imports: import sys
  import warnings
  from functools import partial, reduce
  import numpy
  import pytensor
  import pytensor.sparse
  import pytensor.tensor
  import pytensor.tensor.slinalg
  import scipy
  import scipy.sparse
  from pytensor.graph.basic import Apply
  from pytensor.graph.op import Op
  from pytensor.tensor import abs, and_, arccos, arccosh, arcsin, arcsinh, arctan, arctanh, broadcast_to, ceil, clip, concatenate, constant, cos, cosh, cumprod, cumsum, dot, eq, erf, erfc, erfcinv, erfinv, exp, flatten, floor, full, full_like, ge, gt, le, log, log1pexp, logaddexp, logsumexp, lt, matmul, max, maximum, mean, min, minimum, neq, ones, ones_like, or_, prod, sgn, sigmoid, sin, sinh, sqr, sqrt, stack, sum, switch, tan, tanh, where, zeros, zeros_like
  from pytensor.tensor.linalg import solve_triangular
  from pytensor.tensor.nlinalg import matrix_inverse
  from pytensor.tensor.special import log_softmax, softmax
  from scipy.linalg import block_diag
  from pymc.pytensorf import floatX, ix_, largest_common_dtype
label_desc: Use image node_id 4 for calling a global function with example usage: flat_outer(a, b) and returns: pt