Function parse_sources 

pub fn parse_sources(headers: &HeaderMap) -> Result<CounterSources>

Parses counter sources from message headers.

Sources are stored in the Nats-Counter-Sources header as JSON. The format is: {"source1": {"subject1": "value1", "subject2": "value2"}}

Arguments

• headers - The message headers containing the sources information

Returns

A CounterSources map or None if no sources header is present.