Removed main and added cupy import

src/qibotn/cutn.py

@@ -4,6 +4,7 @@ from cuquantum import cutensornet as cutn
 from mpi4py import MPI  # this line initializes MPI
 import multiprocessing
 from cupy.cuda.runtime import getDeviceCount
+import cupy as cp
 
 
 def eval(qibo_circ, datatype):
@@ -37,23 +38,3 @@ def eval_tn_MPI(qibo_circ, datatype):
     cutn.destroy(handle)
 
     return result, rank
-
-
-if __name__ == "__main__":
-    from qibo.models import QFT
-    import cupy as cp
-    import numpy as np
-
-    num_qubits = 10
-    swaps = True
-    circ_qibo = QFT(num_qubits, swaps)
-
-    dtype = "complex128"
-    sv_mpi, rank = eval_tn_MPI(circ_qibo, dtype)
-
-    if rank == 0:
-        sv_reference = eval(circ_qibo, dtype)
-        state_vec = np.array(circ_qibo())
-        print(f"State vector difference: {abs(sv_mpi-sv_reference).max():0.3e}")
-        assert cp.allclose(sv_mpi, sv_reference)
-        assert cp.allclose(sv_mpi.flatten(), state_vec)