input: Write a function to port a Java code snippet to Python 3. The function should take the Java code as input and return the equivalent Python 3 code. If the input Java code is empty, the function should return an empty string.
  assert port_java_to_python("public class Foo { public int foo( int a, int b ) { return a + b; } }")== "def foo(a, b):\n return a + b"
  assert port_java_to_python("public class Bar { public int bar( int x, int y ) { return x * y; } }")== "def bar(x, y):\n return x * y"
  assert port_java_to_python("")== ""
  assert port_java_to_python("public class Baz { public void baz() { } }")== "def baz():\n pass"
  assert port_java_to_python("public class Qux { public String qux( String s ) { return s.toUpperCase(); } }")== "def qux(s):\n return s.upper()"
output: def port_java_to_python(java_code):
      if not java_code:
          return ""
      method_start = java_code.find("public")
      method_end = java_code.find("}")
      method_code = java_code[method_start:method_end].strip()
      method_name_start = method_code.find("public") + len("public")
      method_name_end = method_code.find("(")
      method_name = method_code[method_name_start:method_name_end].strip().split()[-1]
      params_start = method_code.find("(") + 1
      params_end = method_code.find(")")
      params = method_code[params_start:params_end].split(",")
      params = [param.split()[-1] for param in params]
      params_str = ", ".join(params)
      body_start = method_code.find("{") + 1
      body_end = method_code.rfind("}")
      body = method_code[body_start:body_end].strip()
      if "return" in body:
          body = body.replace("return", "").strip()
          if "toUpperCase" in body:
              body = body.replace("toUpperCase", "upper")
          return f"def {method_name}({params_str}):\n return {body}"
      else:
          return f"def {method_name}({params_str}):\n pass"