@Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        PluginCoordinates other = (PluginCoordinates) obj;
        if (artifactId == null) {
            if (other.artifactId != null)
                return false;
        } else if (!artifactId.equals(other.artifactId))
            return false;
        if (classifier == null) {
            if (other.classifier != null)
                return false;
        } else if (!classifier.equals(other.classifier))
            return false;
        if (groupId == null) {
            if (other.groupId != null)
                return false;
        } else if (!groupId.equals(other.groupId))
            return false;
        if (type == null) {
            if (other.type != null)
                return false;
        } else if (!type.equals(other.type))
            return false;
        if (version == null) {
            if (other.version != null)
                return false;
        } else if (!version.equals(other.version))
            return false;
        return true;
    }
@see java.lang.Object#equals(java.lang.Object)
common/plugin/src/main/java/io/apiman/common/plugin/PluginCoordinates.java