class_docstr: Concatenates to each node attribute the one-hot degree of the corresponding
  node.
  
  The adjacency matrix is expected to have integer entries and the degree is
  cast to integer before one-hot encoding.
  
  **Arguments**
  
  - `max_degree`: the maximum degree of the nodes, i.e., the size of the
  one-hot vectors.
code: def __init__(self, max_degree):
      self.max_degree = max_degree
  
imports: import numpy
  from spektral.utils import one_hot
label_desc: Use image node_id 1 to create a new Degree object  with example: obj = Degree(max_degree)