<｜begin▁of▁sentence｜>### Instruction:
In one of our upcoming training sessions, we will be demonstrating the utility and features of network visualization tools. There's a segment where we need to exemplify how NetworkX, a popular Python library, can be used for such a purpose. To facilitate this demonstration, imagine we're constructing a simple linear connection resembling a corporate hierarchy or a sequential process, composed of four distinct stages or roles.

For this demonstration, please craft an interactive example using NetworkX to forge this linear diagram. We'd like to concentrate on highlighting the primary stage—think of it as the CEO or the initiation phase of a process. You will need to augment this node with specific visual enhancements to make it stand out: amplify its size to symbolize its importance, position it predominately to ensure visibility, and bathe it in a distinctive color to underscore its priority.

Once the graph is skillfully assembled, we'll need to preserve it in a format conducive to sharing and future presentations. Hence, export this graphical representation into a Graph Exchange XML Format (GEXF) file, which we'll label as "corporate_hierarchy.gexf" for easy identification. Be mindful to include the visual attributes of the graph in the export, as this data is crucial for maintaining the visual distinctions when the file is viewed on different platforms.

As a reminder, this is merely a preparatory step for our training workshop. Assist our participants in visualizing the connections within a project or company structure, and ensure that the file is ready for a seamless presentation. Thank you.
### Response:
import networkx as nx

# Create a path graph with 4 nodes
G = nx.path_graph(4)

# Add visualization data to the first node
G.nodes[0]['viz'] = {'size': 54}
G.nodes[0]['viz']['position'] = {'x': 0, 'y': 1}
G.nodes[0]['viz']['color'] = {'r': 0, 'g': 0, 'b': 256}

# Write the graph to a GEXF file
nx.write_gexf(G, 'test.gexf')
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