<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Create a MongoDB query to get the average salary for all employees.
<|im_end|>
<|im_start|>assistant
db.Employees.aggregate([
    { 
    $group: { 
            _id: null, 
            average_salary: { 
                $avg: "$salary" 
            } 
        } 
    }
])<|im_end|>
