MOA is an open source framework for Big Data stream mining. It includes a collection of machine learning algorithms (classification, regression, clustering, outlier detection, concept drift detection and recommender systems) and tools for evaluation.
WeightedkNN and RW_kNN are introduced in the following papers, respectively: https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=10020652 and https://link.springer.com/chapter/10.1007/978-3-030-88942-5_10