Is the graph symbol used in dask a general notation?

Question

Dask is a flexible library for parallel computing in Python.

This piece of code define some simple functions.

def inc(x):
    return x + 1

def double(x):
    return x + 2

def add(x, y):
    return x + y

data = [1, 2, 3, 4, 5]

output = []
for x in data:
    a = inc(x)
    b = double(x)
    c = add(a, b)
    output.append(c)

total = sum(output)

this piece of code wraps the functions above, and defer their execution.

x = dask.delayed(inc)(1)
y = dask.delayed(inc)(2)
z = dask.delayed(add)(x, y)
z.visualize()

and this task graph

question

is the symbol here a general graph notation? is this a kind of graph language, like UML for visualizing the design of a system, used to visualize the computation task?