}
            }

            @Override
            public ToolchainPrivate createDefaultToolchain() {
                try {
                    return v4Factory
                            .createDefaultToolchain()
                            .map(ToolchainManagerFactory.this::getToolchainV3)
                            .orElse(null);

        when(toolchainFactoryBasicType.createDefaultToolchain()).thenReturn(Optional.of(basicToolchain));
        org.apache.maven.api.Toolchain rareToolchain = mock(org.apache.maven.api.Toolchain.class);
        when(toolchainFactoryRareType.createDefaultToolchain()).thenReturn(Optional.of(rareToolchain));

        // execute

                    "Non-existing JDK home configuration at " + normal.toAbsolutePath());
        }

        return jtc;
    }

    @Override
    public ToolchainPrivate createDefaultToolchain() {
        // not sure it's necessary to provide a default toolchain here.
        // only version can be eventually supplied.
        return null;
    }

    protected Logger getLogger() {