input: from typing import Callable
  
  def port_java_to_python(java_code: str) -> Callable:
      """Port a given Java code snippet to Python 3. The input Java code should be a string that defines a class with a single method. The function should return a Python callable equivalent to that method.
      
      Example:
      >>> port_java_to_python("""public class Foo {
        public int foo( int a, int b ) {
          return a + b;
        }
      }""")
      <function foo at 0x7f8b8c0b7d08>
      """
      # Implementation here
output:     
      import re
  
      def extract_method_info(java_code):
          method_pattern = re.compile(r'public\s+(\w+)\s+(\w+)\s*\(([^)]*)\)\s*\{([^}]*)\}', re.DOTALL)
          match = method_pattern.search(java_code)
          if match:
              return match.group(1), match.group(2), match.group(3), match.group(4)
          return None, None, None, None
  
      def convert_type(java_type):
          type_map = {
              'int': 'int',
              'float': 'float',
              'double': 'float',
              'String': 'str',
              'boolean': 'bool',
              'void': 'None'
          }
          return type_map.get(java_type, 'object')
  
      def convert_params(params):
          if not params:
              return []
          param_list = params.split(',')
          return [tuple(p.strip().split()[-2:]) for p in param_list]
  
      def convert_body(body):
          body = body.strip()
          if body.startswith('return'):
              return body
          return f'return {body}'
  
      return_type, method_name, params, body = extract_method_info(java_code)
      if not method_name:
          raise ValueError("No valid method found in the Java code.")
  
      param_list = convert_params(params)
      param_defs = ', '.join(f'{p[1]}: {convert_type(p[0])}' for p in param_list)
      return_type = convert_type(return_type)
      body = convert_body(body)
  
      exec(f'def {method_name}({param_defs}):\n    {body}', globals())
      return globals()[method_name]
  