function _multiplyVectorMatrix(a, b) {
    // process storage
    if (b.storage() !== 'dense') {
      throw new Error('Support for SparseMatrix not implemented');
    }

    return _multiplyVectorDenseMatrix(a, b);
  }
C = A * B

@param {Matrix} a            Dense Vector   (M)
@param {Matrix} b            Matrix         (MxN)

@return {Matrix}             Dense Vector   (N)