code: private java.nio.ByteBuffer getWritingRow() {
          final int row = this.writerIndex / this.localCapacity;
          if (row >= this.storage.size()) {
              final java.nio.ByteBuffer buf = java.nio.ByteBuffer.allocate(this.localCapacity);
              this.storage.add(buf);
              return buf;
          }
  
          return this.storage.get(row);
      }
docs: Get which "row" we currently are working with for writing
  
  @return