EmptyVeLaEnvironment.java
/**
* VStar: a statistical analysis tool for variable star data.
* Copyright (C) 2010 AAVSO (http://www.aavso.org/)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.aavso.tools.vstar.vela;
import java.util.Optional;
/**
* A VeLa environment that is backed by nothing, i.e. has no content.
*/
public class EmptyVeLaEnvironment extends VeLaEnvironment {
@Override
public Optional<Operand> lookup(String name) {
return Optional.empty();
}
}