_findDeveloperKey() {
		// We already have a developer key
		if(this._developerKey) return Promise.resolve(this._developerKey);

		// Call and fetch the key or set a new key
		return this.call('get_lumi_dpf_aes_key')
			.then(result => {
				let key = result[0];
				if(key && key.length === 16) {
					// This is a valid key, store it
					return key;
				}

				key = generateKey();
				return this.call('set_lumi_dpf_aes_key', [ key ]);
			})
			.then(key => this._setDeveloperKey(key));
	}
Either resolve the developer key or setup a new one.