old_contents: import eigenpy
  
  import numpy as np
  import numpy.linalg as la
  
  dim = 100
  A = np.random.rand(dim,dim)
  
  A = (A + A.T)*0.5 + np.diag(10. + np.random.rand(dim))
  
  minres = eigenpy.MINRES(A)
  
  X = np.random.rand(dim,20)
  B = A.dot(X)
  X_est = minres.solve(B)
  assert eigenpy.is_approx(A.dot(X_est),B)
  
new_contents: import eigenpy
  
  import numpy as np
  import numpy.linalg as la
  
  dim = 100
  A = np.eye(dim)
  
  minres = eigenpy.MINRES(A)
  
  X = np.random.rand(dim,20)
  B = A.dot(X)
  X_est = minres.solve(B)
  assert eigenpy.is_approx(A.dot(X_est),B,1e-6)
  
subject: change A matrix