public static Condition newUserAgentCondition(StringComparisonType comparisonType, String value) {
        return new StringCondition(comparisonType, USER_AGENT_CONDITION_KEY, value);
    }
Constructs a new access control policy condition that tests the incoming request's user agent field against the
specified value, using the specified comparison type.

<p>
This condition should be used carefully. Since the UserAgent value is provided by the caller in an HTTP header,
unintended parties can use modified or custom browsers to provide any UserAgent value that they choose. As a result,
UserAgent should not be used to prevent unintended parties from making direct AWS requests. You can use it to allow only
specific client applications, and only after testing your policy.

@param comparisonType
           The type of string comparison to perform when testing an
           incoming request's user agent field with the specified value.
@param value
           The value against which to compare the incoming request's user
           agent.

@return A new access control policy condition that tests an incoming
        request's user agent field.
aws-java-sdk-core/src/main/java/com/amazonaws/auth/policy/conditions/ConditionFactory.java