public String getMasterUsername() {
        return this.masterUsername;
    }
<p>
The name for the master user.
</p>
<p>
<b>MySQL</b>
</p>
<p>
Constraints:
</p>
<ul>
<li>
<p>
Required for MySQL.
</p>
</li>
<li>
<p>
Must be 1 to 16 letters or numbers. Can contain underscores.
</p>
</li>
<li>
<p>
First character must be a letter.
</p>
</li>
<li>
<p>
Can't be a reserved word for the chosen database engine.
</p>
<p>
For more information about reserved words in MySQL 5.6 or 5.7, see the Keywords and Reserved Words articles for
<a href="https://dev.mysql.com/doc/refman/5.6/en/keywords.html">MySQL 5.6</a>, <a
href="https://dev.mysql.com/doc/refman/5.7/en/keywords.html">MySQL 5.7</a>, or <a
href="https://dev.mysql.com/doc/refman/8.0/en/keywords.html">MySQL 8.0</a>.
</p>
</li>
</ul>
<p>
<b>PostgreSQL</b>
</p>
<p>
Constraints:
</p>
<ul>
<li>
<p>
Required for PostgreSQL.
</p>
</li>
<li>
<p>
Must be 1 to 63 letters or numbers. Can contain underscores.
</p>
</li>
<li>
<p>
First character must be a letter.
</p>
</li>
<li>
<p>
Can't be a reserved word for the chosen database engine.
</p>
<p>
For more information about reserved words in MySQL 5.6 or 5.7, see the Keywords and Reserved Words articles for
<a href="https://www.postgresql.org/docs/9.6/sql-keywords-appendix.html">PostgreSQL 9.6</a>, <a
href="https://www.postgresql.org/docs/10/sql-keywords-appendix.html">PostgreSQL 10</a>, <a
href="https://www.postgresql.org/docs/11/sql-keywords-appendix.html">PostgreSQL 11</a>, and <a
href="https://www.postgresql.org/docs/12/sql-keywords-appendix.html">PostgreSQL 12</a>.
</p>
</li>
</ul>

@return The name for the master user.</p>
        <p>
        <b>MySQL</b>
        </p>
        <p>
        Constraints:
        </p>
        <ul>
        <li>
        <p>
        Required for MySQL.
        </p>
        </li>
        <li>
        <p>
        Must be 1 to 16 letters or numbers. Can contain underscores.
        </p>
        </li>
        <li>
        <p>
        First character must be a letter.
        </p>
        </li>
        <li>
        <p>
        Can't be a reserved word for the chosen database engine.
        </p>
        <p>
        For more information about reserved words in MySQL 5.6 or 5.7, see the Keywords and Reserved Words
        articles for <a href="https://dev.mysql.com/doc/refman/5.6/en/keywords.html">MySQL 5.6</a>, <a
        href="https://dev.mysql.com/doc/refman/5.7/en/keywords.html">MySQL 5.7</a>, or <a
        href="https://dev.mysql.com/doc/refman/8.0/en/keywords.html">MySQL 8.0</a>.
        </p>
        </li>
        </ul>
        <p>
        <b>PostgreSQL</b>
        </p>
        <p>
        Constraints:
        </p>
        <ul>
        <li>
        <p>
        Required for PostgreSQL.
        </p>
        </li>
        <li>
        <p>
        Must be 1 to 63 letters or numbers. Can contain underscores.
        </p>
        </li>
        <li>
        <p>
        First character must be a letter.
        </p>
        </li>
        <li>
        <p>
        Can't be a reserved word for the chosen database engine.
        </p>
        <p>
        For more information about reserved words in MySQL 5.6 or 5.7, see the Keywords and Reserved Words
        articles for <a href="https://www.postgresql.org/docs/9.6/sql-keywords-appendix.html">PostgreSQL 9.6</a>,
        <a href="https://www.postgresql.org/docs/10/sql-keywords-appendix.html">PostgreSQL 10</a>, <a
        href="https://www.postgresql.org/docs/11/sql-keywords-appendix.html">PostgreSQL 11</a>, and <a
        href="https://www.postgresql.org/docs/12/sql-keywords-appendix.html">PostgreSQL 12</a>.
        </p>
        </li>
aws-java-sdk-lightsail/src/main/java/com/amazonaws/services/lightsail/model/CreateRelationalDatabaseRequest.java