Arithmetica.MathExpressionContext.ResolveSafe C# (CSharp) Method

        internal MathExpression ResolveSafe(string variable)
        {
            try
            {
                _lock.EnterReadLock();

                if (!_lookup.ContainsKey(variable))
                {
                    return null;
                }
                return _lookup[variable];
            }
            finally
            {
                _lock.ExitReadLock();
            }
        }