be more explicit about the return type of matrixMultiply in JavaDocs.
@@ -100,7 +100,8 @@ public abstract class DoubleVertex extends Vertex<DoubleTensor> implements Doubl
* Matrix product of two vertices
*
* @param that a double vertex to matrix multiply
- * @return a vertex that represents the matrix multiplication of two vertices.
+ * @return a vertex that represents the matrix multiplication of two vertices. Note that this operation
+ * does that always return a MatrixMultiplicationVertex.
* - If both left and right operands are rank 2, they are multiplied like conventional matrices.
* - If both left and right operands are rank 1, they are promoted to a matrix by prepending a 1 to its dimensions.
* After matrix multiplication, it is reshaped to be a scalar. This is essentially a dot product.
