public LadderSequence Multiply()

in Chemistry/src/DataModel/LadderOperator/LadderSequence.cs [185:244]
27 lines of code
5 McCabe index (conditional complexity)

        public LadderSequence<TIndex> Multiply(
            LadderSequence<TIndex> left, 
            LadderSequence<TIndex> right) 
            => new LadderSequence<TIndex>(left.Sequence.Concat(right.Sequence), left.Coefficient * right.Coefficient);
        
        /// <summary>
        /// Counts the number of unique system indices across all <see cref="LadderOperator{TIndex}"/> terms
        /// in a <see cref="LadderSequence{TIndex}"/>
        /// </summary>
        /// <returns>Number of unique system indices.</returns>
        public int UniqueIndices() => Sequence.Select(o => o.Index).Distinct().Count();

        /// <summary>
        /// Returns a copy of the ladder sequence base class.
        /// </summary>
        /// <returns>Base class of this sequence of ladder operators.</returns>
        public LadderSequence<TIndex> ToLadderSequence() => new LadderSequence<TIndex>(Sequence, Coefficient);

        /// <summary>
        /// Returns list of indices of the ladder operator sequence.
        /// </summary>
        /// <returns>Sequence of integers. </returns>
        public IEnumerable<TIndex> ToIndices() => Sequence.Select(o => (TIndex) o.Index);

        /// <summary>
        /// Returns sequence of raising and lowering types of the ladder operator sequence.
        /// </summary>
        /// <returns>Sequence of raising an lowering operators.</returns>
        public IEnumerable<RaisingLowering> ToRaisingLowering() => Sequence.Select(o => o.Type);

        /// <summary>
        /// Returns a human-readable description of this object.
        /// </summary>
        public override string ToString() => $"{Coefficient} * {string.Join(" ", Sequence)}";

        #region Equality Testing
        public override bool Equals(object obj) => (obj is LadderSequence<TIndex> x) ? Equals(x) : false;

        public bool Equals(LadderSequence<TIndex> x)
        {
            // If parameter is null, return false.
            if (ReferenceEquals(x, null))
            {
                return false;
            }

            // Optimization for a common success case.
            if (ReferenceEquals(this, x))
            {
                return true;
            }

            // If run-time types are not exactly the same, return false.
            if (GetType() != x.GetType())
            {
                return false;
            }
            // Return true if the fields match.
            return Sequence.SequenceEqual(x.Sequence);
        }