code: function encodePlainObject( encoder, object ) {
  
  	// Extract plain object signature
  	var o_keys =Object.keys(object);
  		// signature = o_keys.join("+"),
  	var sid = encoder.getSignatureID( o_keys );
  
  	// Collect values of all properties
  	var values = [];
  	for (var i=0, len=o_keys.length; i<len; ++i)
  		values.push( object[o_keys[i]] );
  
  	encoder.log(LOG.PLO, "plain["+sid+"], signature="+o_keys.toString()+", sid="+sid);
  
  	// Split entity ID in a 11-bit number
  	var sid_hi = (sid & 0x700) >> 8,
  		sid_lo =  sid & 0xFF;
  
  	// We have a known entity ID, re-use it
  	encoder.stream8.write( pack1b( PRIM_OP.OBJECT | OBJ_OP.PLAIN_LOOKUP | sid_hi ) );
  	encoder.stream8.write( pack1b( sid_lo ) );
  	encoder.counters.op_prm+=2;
  
  	// Keep iref and encode
  	encodeArray( encoder, values );
  
  }
docs: Encode plain object