final List<TypeParameterSignature> parameterSignatures;

    TypeSignature(TypeVariable<Method>[] parameters) {
      parameterSignatures =
          transform(
              asList(parameters),
              new Function<TypeVariable<?>, TypeParameterSignature>() {
                @Override
                public TypeParameterSignature apply(TypeVariable<?> from) {
                  return new TypeParameterSignature(from);

    TypeToken<?> parameterType = parameters.get(0).getType();
    Type[] typeArgs = ((ParameterizedType) parameterType.getType()).getActualTypeArguments();
    assertThat(typeArgs).hasLength(1);
    TypeVariable<?> captured = (TypeVariable<?>) typeArgs[0];
    assertThat(captured.getBounds()).asList().containsExactly(Object.class);
    assertThat(new TypeToken<List<?>>() {}.isSupertypeOf(parameterType)).isTrue();
  }

import java.lang.reflect.Constructor;
import java.lang.reflect.GenericDeclaration;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.TypeVariable;
import java.util.Collections;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit tests for {@link Invokable}.
 *

            || isNullableTypeVariable(param.getAnnotatedType().getType());
      }

      boolean isNullableTypeVariable(Type type) {
        if (!(type instanceof TypeVariable)) {
          return false;
        }
        TypeVariable<?> typeVar = (TypeVariable<?>) type;
        for (AnnotatedType bound : typeVar.getAnnotatedBounds()) {
          // Until Java 15, the isNullableTypeVariable case here won't help:

import java.lang.annotation.Target;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;

import java.lang.annotation.Target;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;