function assertBlockVarModels(block, varIds) {
  const expectedVarModels = [];
  for (let i = 0; i < varIds.length; i++) {
    expectedVarModels.push(block.workspace.getVariableById(varIds[i]));
  }
  assert.sameDeepOrderedMembers(block.getVarModels(), expectedVarModels);
}
Asserts that the procedure definition or call block has the expected var
models.
@param {!Blockly.Block} block The procedure definition or call block to
   check.
@param {!Array<string>} varIds An array of variable ids.