@Override
    public boolean isUsernameProhibited() throws GuacamoleException {
        return environment.getProperty(PROHIBIT_USERNAME, false);
    }
Creates a new PostgreSQLPasswordPolicy which reads the details of the
policy from the properties exposed by the given environment.

@param environment
    The environment from which password policy properties should be
    read.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/apache/guacamole/auth/postgresql/conf/PostgreSQLPasswordPolicy.java