function checkVariableValues(container, name, type, id) {
  var variable = container.getVariableById(id);
  assertNotUndefined(variable);
  assertEquals(name, variable.name);
  assertEquals(type, variable.type);
  assertEquals(id, variable.getId());
}
Check if a variable with the given values exists.
@param {Blockly.Workspace|Blockly.VariableMap} container The workspace  or
    variableMap the checked variable belongs to.
@param {!string} name The expected name of the variable.
@param {!string} type The expected type of the variable.
@param {!string} id The expected id of the variable.