docstr: block_diag with scalar and 1d arguments 
docstr_tok: ["block_diag","with","scalar","and","1d","arguments"]
code: def test_block_diag_scalar_1d_args(self):
      """block_diag with scalar and 1d arguments"""
      # one 1d matrix and a scalar
      assert_array_equal(
          construct.block_diag([[2, 3], 4]).toarray(),
          [[2, 3, 0], [0, 0, 4]],
      )
  
imports: import numpy
  from numpy import array
  from numpy.testing import assert_equal, assert_, assert_array_equal, assert_array_almost_equal_nulp
  import pytest
  from pytest import raises
  from scipy._lib._testutils import check_free_memory
  from scipy._lib._util import check_random_state
  from scipy.sparse import csr_matrix, coo_matrix, construct
  from scipy.sparse.construct import rand
  from scipy.sparse.sputils import matrix
label_desc: Use image node_id 21 for calling the TestConstructUtils obj's underlying member method code with example usage: obj.test_block_diag_scalar_1d_args() without return types