old_contents: import _ast
  from jaspyx.visitor import BaseVisitor
  
  
  class AugAssign(BaseVisitor):
      def visit_AugAssign(self, node):
          attr = getattr(self, 'AugAssign_%s' % node.op.__class__.__name__, None)
          if attr is None:
              # Rewrite the expression as an assignment using a BinOp
              self.visit(_ast.Assign(
                  [node.target],
                  _ast.BinOp(
                      _ast.Name(node.target.id, _ast.Load()),
                      node.op,
                      node.value
                  )
              ))
          else:
              attr(node.target, node.op, node.value)
  
      for key, value in {
          'Add': ' += ',
          'Sub': ' -= ',
          'Mult': ' *= ',
          'Div': ' /= ',
          'Mod': ' %= ',
          'BitAnd': ' &= ',
          'BitOr': ' |= ',
          'BitXor': ' ^= ',
      }.items():
          def gen_op(op):
              def f_op(self, target, value):
                  self.indent()
                  self.group(
                      [target, value],
                      prefix='',
                      infix=op,
                      suffix='',
                  )
                  self.finish()
          exec 'AugAssign_%s = gen_op("%s")' % (key, value)
  
new_contents: import _ast
  from jaspyx.visitor import BaseVisitor
  
  
  class AugAssign(BaseVisitor):
      def visit_AugAssign(self, node):
          attr = getattr(self, 'AugAssign_%s' % node.op.__class__.__name__, None)
          if attr is None:
              # Rewrite the expression as an assignment using a BinOp
              self.visit(_ast.Assign(
                  [node.target],
                  _ast.BinOp(
                      _ast.Name(node.target.id, _ast.Load()),
                      node.op,
                      node.value
                  )
              ))
          else:
              attr(node.target, node.value)
  
      for key, value in {
          'Add': ' += ',
          'Sub': ' -= ',
          'Mult': ' *= ',
          'Div': ' /= ',
          'Mod': ' %= ',
          'BitAnd': ' &= ',
          'BitOr': ' |= ',
          'BitXor': ' ^= ',
      }.items():
          def gen_op(op):
              def f_op(self, target, value):
                  self.indent()
                  self.group(
                      [target, value],
                      prefix='',
                      infix=op,
                      suffix='',
                  )
                  self.finish()
              return f_op
          exec 'AugAssign_%s = gen_op("%s")' % (key, value)
  
subject: Fix augmented assignment.