Mixed integer solving

[ghost]

Hello, I'm using gde3 in the jmetalpy framework to solve the multi-objective problem. Now my problem belongs to a mixed who to find planning problem. The decision variable contains a part of Floating-point arithmetic numbers and integers, but I used the method of solving mixed variables in jmetalpy, but now I have encountered some problems,

from jmetal.algorithm.multiobjective.nsgaii import NSGAII
from jmetal.operator import IntegerPolynomialMutation, PolynomialMutation, SBXCrossover
from jmetal.operator.crossover import CompositeCrossover, IntegerSBXCrossover
from jmetal.operator.mutation import CompositeMutation
from jmetal.problem.multiobjective.unconstrained import MixedIntegerFloatProblem
from jmetal.util.solution import (
    get_non_dominated_solutions,
    print_function_values_to_file,
    print_variables_to_file,
)
from jmetal.util.termination_criterion import StoppingByEvaluations

if __name__ == "__main__":
    problem = MixedIntegerFloatProblem(10, 10, 100, -100, -1000, 1000)

    max_evaluations = 25000
    algorithm = NSGAII(
        problem=problem,
        population_size=100,
        offspring_population_size=100,
        mutation=CompositeMutation([IntegerPolynomialMutation(0.01, 20), PolynomialMutation(0.01, 20.0)]),
        crossover=CompositeCrossover(
            [
                IntegerSBXCrossover(probability=1.0, distribution_index=20),
                SBXCrossover(probability=1.0, distribution_index=20),
            ]
        ),
        termination_criterion=StoppingByEvaluations(max_evaluations=max_evaluations),
    )

    algorithm.run()
    front = get_non_dominated_solutions(algorithm.get_result())

    # Save results to file
    print_function_values_to_file(front, "FUN." + algorithm.label)
    print_variables_to_file(front, "VAR." + algorithm.label)

    print(f"Algorithm: {algorithm.get_name()}")
    print(f"Problem: {problem.name()}")
    print(f"Computing time: {algorithm.total_computing_time}")

TypeError will be generated in the code: Can't immediately abstract class MixedIntegerProblem with abstract methods name, number_ Of_ Constraints, number_ Of_ Objectives
I am currently using the following code you provided, but the following error occurred. May I ask why