How do i specify keyof

type IncludeOfType<Object, Type> = {
  [K in keyof Object as Object[K] extends Type ? K : never]: Object[K];
};

type T1 = IncludeOfType<{
    Name: string,
    Width: number,
}, number>

type IncludeOfType<Object, Type> = {
  [K in keyof Object as Object[K] extends Type ? K : never]: Object[K];
};

type T1 = IncludeOfType<{
    Name: string,
    Width: number,
}, number>

T extends number ? "T is a number" : "T is not a number";

T extends number ? "T is a number" : "T is not a number";

Name extends WritableInstanceProperties<ConnectedInstance>
typeof Name = ["DisplayName", "ClassName"...etc]

Name extends WritableInstanceProperties<ConnectedInstance>
typeof Name = ["DisplayName", "ClassName"...etc]

typeof Name = ["DisplayName": string..etc]

typeof Name = ["DisplayName": string..etc]

export class ConnectedStat<
    ConnectedInstance extends Instance,
    Name extends ExtractKeys<WritableInstanceProperties<ConnectedInstance>, number>,
> extends SeparatedStat {
    instance: ConnectedInstance;
    conected_to: Name;

    constructor(Name: string, Value: number, ConnectToInstance: ConnectedInstance, InstancePropertyName: Name) {
        super(Name, Value);

        this.instance = ConnectToInstance;
        this.instance[InstancePropertyName] = this.Total.Get();
        this.conected_to = InstancePropertyName;

        this.Total.changed.Connect(() => {
            this.instance[InstancePropertyName] = this.Total.Get();
        });
        this.instance.GetPropertyChangedSignal(InstancePropertyName).Connect(() => {
            this.instance[InstancePropertyName] = this.Total.Get();
        });
    }
}

export class ConnectedStat<
    ConnectedInstance extends Instance,
    Name extends ExtractKeys<WritableInstanceProperties<ConnectedInstance>, number>,
> extends SeparatedStat {
    instance: ConnectedInstance;
    conected_to: Name;

    constructor(Name: string, Value: number, ConnectToInstance: ConnectedInstance, InstancePropertyName: Name) {
        super(Name, Value);

        this.instance = ConnectToInstance;
        this.instance[InstancePropertyName] = this.Total.Get();
        this.conected_to = InstancePropertyName;

        this.Total.changed.Connect(() => {
            this.instance[InstancePropertyName] = this.Total.Get();
        });
        this.instance.GetPropertyChangedSignal(InstancePropertyName).Connect(() => {
            this.instance[InstancePropertyName] = this.Total.Get();
        });
    }
}