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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def initialize_api(flask_app):
 """Initialize an API."""

    if not flask_restplus:
        return

    api = flask_restplus.Api(version="1.0", title="My Example API")
    api.add_resource(HelloWorld, "/hello")

    blueprint = flask.Blueprint("api", __name__, url_prefix="/api")
    api.init_app(blueprint)
    flask_app.register_blueprint(blueprint)