Constructor that takes in a single 'primary' principal of the account and its corresponding credentials,
associated with the specified realm.
<p/>
This is a convenience constructor and will construct a {@link PrincipalCollection PrincipalCollection} based
on the {@code principal} and {@code realmName} argument.
@param principal the 'primary' principal associated with the specified realm.
@param credentials the credentials that verify the given principal.
@param realmName the realm from where the principal and credentials were acquired.
Constructor that takes in a single 'primary' principal of the account and its corresponding credentials, associated with the specified realm. <p/> This is a convenience constructor and will construct a {@link PrincipalCollection PrincipalCollection} based on the {@code principal} and {@code realmName} argument.
@param principal the 'primary' principal associated with the specified realm. @param credentials the credentials that verify the given principal. @param realmName the realm from where the principal and credentials were acquired.