Unable to decode a json string to a python object using jsonpickle

My class structure is as follows -

class HelloWorld (object):
    def __init__(self, name, i, id):
        self.name = name
        self.i = i
        self.id = id

The I'm creating an object

p = HelloWorld('pj', 3456, '1234')

and passing this object to a definition, where I use jsonpickle.encode and jsonpickle.decode as follows

>>>print(type(p)) 
    <class 'HelloWorld'>
 >>>x = jsonpickle.encode(p)        
 >>>print(x)
    {"i": 3456, "name": "pj", "py/object": "__builtin__.HelloWorld", "id": "1234"}
 >>>y = jsonpickle.decode(x)
 >>>print(type(y))
    <class 'dict'>

I don't understand why I'm not able to decode it back to the original object, even though the distinguishing py/object is also present.

Can anyone please suggest what am I doing wrong?

Adding the code which generate's the dynamic class for above mentioned use case.

def _create_pojo(self, pojo_class_name, param_schema):

    #extracting the properties from the parameter 'schema'        
    pojo_properties = param_schema['properties']

    #creating a list of property keys
    pojo_property_list = []
    for key in pojo_properties:
        pojo_property_list.append(key)

    source = \
        "class %s (object):\n" % ( pojo_class_name )       
    source += "    def __init__(self, %s" % ', '.join(pojo_property_list) +"):\n" #defining __init__ for the class
    for prop in pojo_property_list: #creating a variable in the __init__ method for each property in the property list
        source += "        self.%s = %s\n" % (prop, prop)

    #generating the class code
    class_code = compile( source, "<generated class>", "exec" )
    fakeglobals = {}
    eval( class_code, {"object" : object}, fakeglobals )
    result = fakeglobals[ pojo_class_name ]        
    result ._source = source
    pprint.pprint(source)       

    self._object_types[ pojo_class_name ] = result
    return result