<｜begin▁of▁sentence｜>### Instruction:
While working in a research laboratory, you are studying the interactions of different microorganisms in a contained environment with the aim of understanding their biology and functions and developing potential treatments, vaccines, or biotechnological applications. As you are analyzing the data, you also need to create a visualization of the microbial interactions.

To achieve this, you have generated a network graph using Python's NetworkX library to represent the relationships between different microorganisms. Now, you need to store this graph in a .dot file for further analysis. Meanwhile, you are also utilizing the igraph library for some long-running tasks. In the process, you want to check if a progress handler has been set for these tasks.

In the context of this microbiology research scenario, you need to integrate the technical functionalities seamlessly with your laboratory analysis.
### Response:
from networkx.drawing.nx_pydot import write_dot
import networkx as nx

# Assume we have a NetworkX graph called G
G = nx.complete_graph(5)

# Write to a dot file
write_dot(G, 'complete_graph.dot')

# Example use of the igraph Shell.Shell.get_progress_handler()
# This is a mock function as the igraph library does not include a Shell module

# Assuming we have a Shell object from igraph with the method get_progress_handler
shell = Shell()
progress_handler = shell.get_progress_handler()
if progress_handler:
    print('Progress handler exists and is returned')
else:
    print('No progress handler is set')
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