ta4j/src/main/java/eu/verdelhan/ta4j/Decimal.java
public Decimal plus(Decimal augend) {
        if ((this == NaN) || (augend == NaN)) {
            return NaN;
        }
        return new Decimal(delegate.add(augend.delegate, MATH_CONTEXT));
    }
public Decimal plus(Decimal augend) {
        if ((this == NaN) || (augend == NaN)) {
            return NaN;
        }
        return new Decimal(delegate.add(augend.delegate, MATH_CONTEXT));
    }
Returns a {@code Decimal} whose value is {@code (this + augend)},
with rounding according to the context settings.
@param augend value to be added to this {@code Decimal}.
@return {@code this + augend}, rounded as necessary
@see BigDecimal#add(java.math.BigDecimal, java.math.MathContext)