public int getMaxAttempts(int defaultValue) {
		return getProperty(MAX_ATTEMPTS, defaultValue);
	}
Return the 'maxAttempts' property or the default value.
This is used in the retry template's SimpleRetryPolicy
in buses that support retry.
@param defaultValue The default value.
@return The property or default value.
spring-xd-messagebus-spi/src/main/java/org/springframework/xd/dirt/integration/bus/AbstractBusPropertiesAccessor.java