ExtensionContext
The context information of the extension.
struct ExtensionContext {
    bool isValid;
    uid_t uid;
    const char *providerName;
    const char *extensionName;
    ExtensionContext():isValid(false), uid(0), providerName(NULL), extensionName(NULL) {}
};
            
            
            
            
             Attributes
- isValid
 - Whether the uid in ExtensionContext is valid: 
true: The uid is valid.false: The uid is invalid.
 - uid
 - The user ID. 0 represents a local user, while greater than 0 represents a remote user.
 - providerName
 - The name of the extension provider.
 - extensionName
 - The name of the extension.