System.Data.Common.DbConnectionOptions.ExpandKeyword C# (CSharp) Method

        internal string ExpandKeyword(string keyword, string replacementValue)
        {
            // preserve duplicates, updated keyword value with replacement value
            // if keyword not specified, append to end of the string
            bool expanded = false;
            int copyPosition = 0;

            var builder = new StringBuilder(_usersConnectionString.Length);
            for (NameValuePair current = _keyChain; null != current; current = current.Next)
            {
                if ((current.Name == keyword) && (current.Value == this[keyword]))
                {
                    // only replace the parse end-result value instead of all values
                    // so that when duplicate-keywords occur other original values remain in place
                    AppendKeyValuePairBuilder(builder, current.Name, replacementValue, _useOdbcRules);
                    builder.Append(';');
                    expanded = true;
                }
                else
                {
                    builder.Append(_usersConnectionString, copyPosition, current.Length);
                }
                copyPosition += current.Length;
            }

            if (!expanded)
            {
                Debug.Assert(!_useOdbcRules, "ExpandKeyword not ready for Odbc");
                AppendKeyValuePairBuilder(builder, keyword, replacementValue, _useOdbcRules);
            }
            return builder.ToString();
        }