input: Write a function to generate an HTML page containing a table with some employee data. The function should take a list of dictionaries where each dictionary represents an employee with keys 'Name', 'Job Title', 'Department', and 'Salary'. The function should return a string representing the HTML page.
  assert generate_html_table([{'Name': 'John Doe', 'Job Title': 'Senior Developer', 'Department': 'IT', 'Salary': '$120,000'}, {'Name': 'Jane Doe', 'Job Title': 'Manager', 'Department': 'Finance', 'Salary': '$95,000'}, {'Name': 'Tim Smith', 'Job Title': 'Junior Developer', 'Department': 'IT', 'Salary': '$55,000'}])=='<html>\n  <head>\n    <title>Employee Data</title>\n  </head>\n  <body>\n    <table>\n      <thead>\n        <tr>\n          <th>Name</th>\n          <th>Job Title</th>\n          <th>Department</th>\n          <th>Salary</th>\n        </tr>\n      </thead>\n      <tbody>\n        <tr>\n          <td>John Doe</td>\n          <td>Senior Developer</td>\n          <td>IT</td>\n          <td>$120,000</td>\n        </tr>\n        <tr>\n          <td>Jane Doe</td>\n          <td>Manager</td>\n          <td>Finance</td>\n          <td>$95,000</td>\n        </tr>\n        <tr>\n          <td>Tim Smith</td>\n          <td>Junior Developer</td>\n          <td>IT</td>\n          <td>$55,000</td>\n        </tr>\n      </tbody>\n    </table>\n  </body>\n</html>'
  assert generate_html_table([])=='<html>\n  <head>\n    <title>Employee Data</title>\n  </head>\n  <body>\n    <table>\n      <thead>\n        <tr>\n          <th>Name</th>\n          <th>Job Title</th>\n          <th>Department</th>\n          <th>Salary</th>\n        </tr>\n      </thead>\n      <tbody>\n      </tbody>\n    </table>\n  </body>\n</html>'
  assert generate_html_table([{'Name': 'Alice Brown', 'Job Title': 'Marketing Specialist', 'Department': 'Marketing', 'Salary': '$70,000'}])=='<html>\n  <head>\n    <title>Employee Data</title>\n  </head>\n  <body>\n    <table>\n      <thead>\n        <tr>\n          <th>Name</th>\n          <th>Job Title</th>\n          <th>Department</th>\n          <th>Salary</th>\n        </tr>\n      </thead>\n      <tbody>\n        <tr>\n          <td>Alice Brown</td>\n          <td>Marketing Specialist</td>\n          <td>Marketing</td>\n          <td>$70,000</td>\n        </tr>\n      </tbody>\n    </table>\n  </body>\n</html>'
output: def generate_html_table(employees):
      table_rows = "\n".join([f"        <tr>\n          <td>{emp['Name']}</td>\n          <td>{emp['Job Title']}</td>\n          <td>{emp['Department']}</td>\n          <td>{emp['Salary']}</td>\n        </tr>" for emp in employees])
      return f"""<html>
    <head>
      <title>Employee Data</title>
    </head>
    <body>
      <table>
        <thead>
          <tr>
            <th>Name</th>
            <th>Job Title</th>
            <th>Department</th>
            <th>Salary</th>
          </tr>
        </thead>
        <tbody>
  {table_rows}
        </tbody>
      </table>
    </body>
  </html>"""