I have a RabbitMQ 3.4.2 instance with a web management plugin installed.
When I push to the message {\'operationId\': 194} to the queue using Python\'s komb
{\'operationId\': 194}
I had to use content_type instead of content-type (an underscore instead of a hyphen).
content_type
content-type
This is a pretty questionable design decision, because the standard everybody knows is content-type.