code: def _build_ast(self):
      coef = utils.to_2d_array(self._get_coef())
      intercept = utils.to_1d_array(self._get_intercept())
  
      if coef.shape[0] == 1:
          return self._final_transform(
              _linear_to_ast(coef[0], intercept[0])
          )
  
      exprs = [
          self._final_transform(
              _linear_to_ast(coef[idx], intercept[idx])
          )
          for idx in range(coef.shape[0])
      ]
      return ast.VectorVal(exprs)
  
imports: import math
  import numpy
  from m2cgen import ast
  from m2cgen.assemblers import utils
  from m2cgen.assemblers.base import ModelAssembler
label_desc: Use image node_id 2 for calling the BaseLinearModelAssembler obj's underlying member method code with example usage: obj._build_ast() and returns: ast, self