camel - spring:bean syntax with dynamic class casting - apache-camel

Question

I'm attempting to convert the following Java object initalization with dynamic class casting to camel spring bean syntax. I'm adding my broken spring bean sample as well. I dont have much familiarity with spring beans, so would very much appreciate some input. The Java syntax is:
import com.amazonaws.auth.STSAssumeRoleSessionCredentialsProvider;
STSAssumeRoleSessionCredentialsProvider credentials = new STSAssumeRoleSessionCredentialsProvider.Builder(
"arn:aws:iam::***:role/myRole-QA", "sessionName").build();
and broken spring bean:
<spring:bean id="sqsCredentials" class="com.amazonaws.auth.STSAssumeRoleSessionCredentialsProvider.Builder" >
<spring:constructor-arg index="0" value="arn:aws:iam:***:role/myRole-QA" />
<spring:constructor-arg index="1" value="sessionName" />
<spring:property name="targetMethod">
<spring:value>build</spring:value>
</spring:property>
</spring:bean>
I'm not sure if what I have for method build is correct, but there are two classes at play: .Builder and just STSAssumeRoleSessionCredentialsProvider. So Builder class returns STSAssumeRoleSessionCredentialsProvider. Most likely i have more then one issue to solve here, but the error I think is related to class mismatch ... much appreciate your time:
Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property 'targetMethod' of bean class
[com.amazonaws.auth.STSAssumeRoleSessionCredentialsProvider$Builder]: Bean property 'targetMethod' is not writable
or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?