text: program main
      use Spoof
      implicit none
  
      type(CSRMatrix)         :: csr_matrix
      type(DiagonalMatrix)    :: dia_matrix
      double precision        :: dense(10,10)
      double precision        :: vec(10)
  
      dense = 42.0D+00
      vec = 10.0D+00
  
      ! Create the matrices
      csr_matrix = CSRMatrix(dense)
      dia_matrix = DiagonalMatrix(dense)
  
      ! Multiply them by vec
      vec = csr_matrix%multiply(vec)              ! vec is filled with 4200
      vec = dia_matrix%multiply(vec)              ! vec is filled with 176400
  
      print *, sum(vec)
  
  end program
  
  