prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  Save and load objects from python
  The last main design issue to be solved for v2.0 concerns saving and loading objects from python.
  
  Pybind11 has some [pickling support](https://pybind11.readthedocs.io/en/stable/advanced/classes.html#pickling-support).
  
  However, the design issue to be addressed is how to serialize objects stored internally as pointers.
  Basically, each pickable object needs to define a GetState function, returning a python tuple of the arguments needed to construct the object. 
  
  ```c++
  py::tuple GetState(const Pickleable &p) { 
              return py::make_tuple(p.Field1(),p.Field2(),...);
  }
  ```
  However, if the `Pickeable` stores a pointer to some abstract object (say Hilbert), then one obviously cannot do: 
  ```c++
  py::tuple GetState(const Pickleable &p) { 
              auto hilbert= p.GetHilbert(); //NO! 
              return py::make_tuple(p.Field1(),p.Field2(),hilbert);
  }
  ```
  
  Suggestions are welcome. 
  
  </issue>
  <code>
  [start of Tutorials/PyNetKet/machine.py]
  1 # Copyright 2018 The Simons Foundation, Inc. - All Rights Reserved.
  2 
  3 # Licensed under the Apache License, Version 2.0 (the "License");
  4 # you may not use this file except in compliance with the License.
  5 # You may obtain a copy of the License at
  6 
  7 #    http://www.apache.org/licenses/LICENSE-2.0
  8 
  9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14 
  15 from __future__ import print_function
  16 import netket as nk
  17 import networkx as nx
  18 import numpy as np
  19 from mpi4py import MPI
  20 import scipy.sparse as sparse
  21 
  22 #Constructing a 1d lattice
  23 g = nk.graph.Hypercube(L=4, ndim=1)
  24 
  25 # Hilbert space of spins from given graph
  26 hi = nk.hilbert.Spin(s=0.5, graph=g)
  27 
  28 #Hamiltonian
  29 ha = nk.operator.Ising(h=1.0, hilbert=hi)
  30 
  31 #Machine
  32 ma = nk.machine.RbmSpin(hilbert=hi, alpha=1)
  33 ma.InitRandomPars(seed=1234, sigma=0.1)
  34 print(ma.GetParameters())
  35 
  36 #Layer
  37 a = np.ones(3, dtype=complex)
  38 b = np.zeros(3, dtype=complex)
  39 act = nk.activation.Tanh()
  40 
  41 act(a, b)
  42 print(b)
  43
  [end of Tutorials/PyNetKet/machine.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/Tutorials/PyNetKet/machine.py b/Tutorials/PyNetKet/machine.py
  --- a/Tutorials/PyNetKet/machine.py
  +++ b/Tutorials/PyNetKet/machine.py
  @@ -19,24 +19,20 @@
   from mpi4py import MPI
   import scipy.sparse as sparse
   
  -#Constructing a 1d lattice
  -g = nk.graph.Hypercube(L=4, ndim=1)
  +# Constructing a 1d lattice
  +g = nk.graph.Hypercube(length=4, n_dim=1)
   
   # Hilbert space of spins from given graph
   hi = nk.hilbert.Spin(s=0.5, graph=g)
   
  -#Hamiltonian
  +# Hamiltonian
   ha = nk.operator.Ising(h=1.0, hilbert=hi)
   
  -#Machine
  +# Machine
   ma = nk.machine.RbmSpin(hilbert=hi, alpha=1)
  -ma.InitRandomPars(seed=1234, sigma=0.1)
  -print(ma.GetParameters())
  +ma.init_random_parameters(seed=1234, sigma=0.1)
   
  -#Layer
  -a = np.ones(3, dtype=complex)
  -b = np.zeros(3, dtype=complex)
  -act = nk.activation.Tanh()
  -
  -act(a, b)
  -print(b)
  +ma.save("test.wf")
  +ma.parameters = np.zeros(ma.n_par)
  +ma.load("test.wf")
  +print(ma.parameters)
  
verification_info: {"golden_diff": "diff --git a/Tutorials/PyNetKet/machine.py b/Tutorials/PyNetKet/machine.py\n--- a/Tutorials/PyNetKet/machine.py\n+++ b/Tutorials/PyNetKet/machine.py\n@@ -19,24 +19,20 @@\n from mpi4py import MPI\n import scipy.sparse as sparse\n \n-#Constructing a 1d lattice\n-g = nk.graph.Hypercube(L=4, ndim=1)\n+# Constructing a 1d lattice\n+g = nk.graph.Hypercube(length=4, n_dim=1)\n \n # Hilbert space of spins from given graph\n hi = nk.hilbert.Spin(s=0.5, graph=g)\n \n-#Hamiltonian\n+# Hamiltonian\n ha = nk.operator.Ising(h=1.0, hilbert=hi)\n \n-#Machine\n+# Machine\n ma = nk.machine.RbmSpin(hilbert=hi, alpha=1)\n-ma.InitRandomPars(seed=1234, sigma=0.1)\n-print(ma.GetParameters())\n+ma.init_random_parameters(seed=1234, sigma=0.1)\n \n-#Layer\n-a = np.ones(3, dtype=complex)\n-b = np.zeros(3, dtype=complex)\n-act = nk.activation.Tanh()\n-\n-act(a, b)\n-print(b)\n+ma.save(\"test.wf\")\n+ma.parameters = np.zeros(ma.n_par)\n+ma.load(\"test.wf\")\n+print(ma.parameters)\n", "issue": "Save and load objects from python\nThe last main design issue to be solved for v2.0 concerns saving and loading objects from python.\r\n\r\nPybind11 has some [pickling support](https://pybind11.readthedocs.io/en/stable/advanced/classes.html#pickling-support).\r\n\r\nHowever, the design issue to be addressed is how to serialize objects stored internally as pointers.\r\nBasically, each pickable object needs to define a GetState function, returning a python tuple of the arguments needed to construct the object. \r\n\r\n```c++\r\npy::tuple GetState(const Pickleable &p) { \r\n            return py::make_tuple(p.Field1(),p.Field2(),...);\r\n}\r\n```\r\nHowever, if the `Pickeable` stores a pointer to some abstract object (say Hilbert), then one obviously cannot do: \r\n```c++\r\npy::tuple GetState(const Pickleable &p) { \r\n            auto hilbert= p.GetHilbert(); //NO! \r\n            return py::make_tuple(p.Field1(),p.Field2(),hilbert);\r\n}\r\n```\r\n\r\nSuggestions are welcome. \n", "before_files": [{"content": "# Copyright 2018 The Simons Foundation, Inc. - All Rights Reserved.\n\n# Licensed under the Apache License, Version 2.0 (the \"License\");\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n\n#    http://www.apache.org/licenses/LICENSE-2.0\n\n# Unless required by applicable law or agreed to in writing, software\n# distributed under the License is distributed on an \"AS IS\" BASIS,\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n# limitations under the License.\n\nfrom __future__ import print_function\nimport netket as nk\nimport networkx as nx\nimport numpy as np\nfrom mpi4py import MPI\nimport scipy.sparse as sparse\n\n#Constructing a 1d lattice\ng = nk.graph.Hypercube(L=4, ndim=1)\n\n# Hilbert space of spins from given graph\nhi = nk.hilbert.Spin(s=0.5, graph=g)\n\n#Hamiltonian\nha = nk.operator.Ising(h=1.0, hilbert=hi)\n\n#Machine\nma = nk.machine.RbmSpin(hilbert=hi, alpha=1)\nma.InitRandomPars(seed=1234, sigma=0.1)\nprint(ma.GetParameters())\n\n#Layer\na = np.ones(3, dtype=complex)\nb = np.zeros(3, dtype=complex)\nact = nk.activation.Tanh()\n\nact(a, b)\nprint(b)\n", "path": "Tutorials/PyNetKet/machine.py"}]}