Function encode_variable_int 

pub fn encode_variable_int<B: BufMut>(buf: &mut B, value: u32) -> Result<()>

Encodes a u32 value as a variable byte integer (compatibility function)

This function provides compatibility with the old variable_byte module API. Prefer using VariableInt::new(value)?.encode(buf) for new code.

Errors

Returns MqttError::ProtocolError if the value exceeds the maximum