import org.gradle.api.provider.ValueSourceParameters;

import javax.annotation.Nullable;

public abstract class EnvironmentVariableValueSource implements ValueSource<String, EnvironmentVariableValueSource.Parameters>, Describable {

    public interface Parameters extends ValueSourceParameters {
        Property<String> getVariableName();
    }

    @Nullable
    @Override
    public String obtain() {

                addSystemPropertiesPrefixedByToFingerprint(prefix, obtainedValue.value.get().uncheckedCast())
                reportUniqueSystemPropertiesPrefixedByInput(prefix)
            }

            is EnvironmentVariableValueSource.Parameters -> {
                addEnvVariableToFingerprint(parameters.variableName.get(), obtainedValue.value.get() as? String)
            }

            is EnvironmentVariablesPrefixedByValueSource.Parameters -> {

Class <org.gradle.api.internal.provider.sources.EnvironmentVariableValueSource$Parameters> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (EnvironmentVariableValueSource.java:0)