an class="memberNameLink"><a href="#countNNZColumns(org.apache.sysds.runtime.matrix.data.MatrixBlock,int,java.util.concurrent.ExecutorService)">countNNZColumns</a></span>&#8203;(<a href="MatrixBlock.html" title="class in org.apache.sysds.runtime.matrix.data">MatrixBlock</a>&nbsp;in,
               int&nbsp;k,
               <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/concurrent/ExecutorService.html?is-external=true" title="class or interface in java.util.concurrent" class