Robotframework -更新json字典中的值给出错误列表：‘AttributeError’对象没有'update‘属性

*** Settings ***
Library    OperatingSystem
Library    Collections
Library    JSONLibrary

*** Test Cases ***
Update JSON Dictionary Value
    ${json_string}=    Set Variable    {"key1": "value1", "key2": "value2"}
    ${json_dict}=    Evaluate    json.loads('''${json_string}''')
    ${key}=    Set Variable    key1
    ${new_value}=    Set Variable    new_value1
    ${key_exists}=    Evaluate    '${key}' in ${json_dict}
    Run Keyword If    ${key_exists}    Update JSON Value    ${json_dict}    ${key}    ${new_value}
    Log    Updated JSON Dictionary: ${json_dict}

*** Keywords ***
Update JSON Value
    [Arguments]    ${json_dict}    ${key}    ${new_value}
    ${json_dict}[${key}]=    ${new_value}
    [Return]    ${json_dict}