void addFunctionAttributes(String functionId, byte[] functionAttributes) {
    idToFunctionAttributes.put(functionId, functionAttributes);
  }
Returns the function attributes defined by the functionId, returns null if no function is found
for the specified functionId

@return byte[]
@throws FunctionException if functionID passed is null
@since GemFire 6.6
geode-core/src/main/java/org/apache/geode/internal/cache/execute/AbstractExecution.java