@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj == null) {
			return false;
		}
		if (!(obj instanceof SparseMatrix)) {
			return false;
		}
		SparseMatrix other = (SparseMatrix) obj;
		if (wordid1 == null) {
			if (other.wordid1 != null) {
				return false;
			}
		} else if (!wordid1.equals(other.wordid1)) {
			return false;
		}
		if (wordid2 == null) {
			if (other.wordid2 != null) {
				return false;
			}
		} else if (!wordid2.equals(other.wordid2)) {
			return false;
		}
		return true;
	}