}

    @Override
    public <T> Option.Value<T> getOption(InternalOption<T> option) {
        String value = startParameterSystemProperties.get(option.getSystemPropertyName());
        if (value == null) {
            value = System.getProperty(option.getSystemPropertyName());
        }
        if (value == null) {
            return Option.Value.defaultValue(option.getDefaultValue());
        } else {

    @Override
    public boolean isEnabled(FeatureFlag flag) {
        broadcaster.flagRead(flag);
        if (flag.getSystemPropertyName() != null) {
            // Can explicitly disable property using system property
            Option.Value<Boolean> option = options.getOption(new InternalFlag(flag.getSystemPropertyName()));
            if (option.isExplicit() || option.get()) {
                return option.get();
            }
        }

/**
 * An internal Gradle option, that can be set using a system property.
 *
 * @param <T> The value of the option.
 */
public interface InternalOption<T> extends Option {
    T getDefaultValue();

    String getSystemPropertyName();

    T convert(String value);

        this.defaultValue = defaultValue;
    }

    @Override
    public Boolean getDefaultValue() {
        return defaultValue;
    }

    @Override
    public String getSystemPropertyName() {
        return systemPropertyName;
    }

    @Override
    public Boolean convert(String value) {
        return !value.equalsIgnoreCase("false");
    }

import javax.annotation.Nullable;

/**
 * A feature flag. Can be enabled via the Settings object or optionally via a system property.
 */
public interface FeatureFlag extends Option {
    @Nullable
    String getSystemPropertyName();

        this.systemPropertyName = systemPropertyName;
        this.defaultValue = defaultValue;
    }

    @Nullable
    @Override
    public String getSystemPropertyName() {
        return systemPropertyName;
    }

    @Override
    public Integer getDefaultValue() {
        return defaultValue;
    }

    @Override
    public Integer convert(String value) {

        this.systemPropertyName = systemPropertyName;
        this.defaultValue = defaultValue;
    }

    @Nullable
    @Override
    public String getSystemPropertyName() {
        return systemPropertyName;
    }

    @Override
    public String getDefaultValue() {
        return defaultValue;
    }

    @Override
    public String convert(String value) {

         * Returns whether the feature is still relevant.
         */
        public boolean isActive() {
            return active;
        }

        @Nullable
        @Override
        public String getSystemPropertyName() {
            return systemPropertyName;
        }
    }

    }

    public static String getDropVfsArgument() {
        return getDropVfsArgument(true);
    }

    public static String getDropVfsArgument(boolean drop) {
        return systemProperty(VFS_DROP_PROPERTY.getSystemPropertyName(), drop);
    }

    public static String getVerboseVfsLoggingArgument() {
        return systemProperty(StartParameterBuildOptions.VfsVerboseLoggingOption.GRADLE_PROPERTY, true);
    }