code: package gr.uom.java.history;
  
  public class ProjectVersionPair {
  	private ProjectVersion fromVersion;
  	private ProjectVersion toVersion;
  	
  	public ProjectVersionPair(ProjectVersion fromVersion, ProjectVersion toVersion) {
  		this.fromVersion = fromVersion;
  		this.toVersion = toVersion;
  	}
  
  	public ProjectVersion getFromVersion() {
  		return fromVersion;
  	}
  
  	public ProjectVersion getToVersion() {
  		return toVersion;
  	}
  
  	public String toString() {
  		return fromVersion.toString() + "-" + toVersion.toString();
  	}
  }
  