To generate test cases for the given problem statement about the convenience store placement, we need to take into account the constraints and the structure of the input and output. The map is divided into hexagonal blocks arranged in a grid, and the goal is to calculate the maximum number of blocks that can be covered from all candidate locations based on the map and the existing convenience stores.

First, let's outline the structure of the input and output based on the problem statement:

**Input:**
1. First line: Two integers \(m\) and \(n\) (1 ≤ \(m, n\) ≤ 100), representing the number of rows and columns of the map.
2. Next \(m\) lines: Each line contains \(n\) integers, where each integer represents whether there is an existing convenience store in that block (1 if there is a store, 0 if there is not).
3. Next line: An integer \(k\) (1 ≤ \(k\) ≤ 100), representing the number of candidate locations for new stores.
4. Next \(k\) lines: Each line contains two integers \(x\) and \(y\) (1 ≤ \(x\) ≤ \(m\), 1 ≤ \(y\) ≤ \(n\)), representing the coordinates of the candidate locations.

**Output:**
- A single integer representing the maximum number of blocks that can be covered by a new store placed in one of the candidate locations.

Here is the test case generator for the problem:

```python
import random

def generate_test_case():
    m = random.randint(1, 100)
    n = random.randint(1, 100)
    
    # Generate the map with existing convenience stores
    map_grid = [[random.choice([0, 1]) for _ in range(n)] for _ in range(m)]
    
    k = random.randint(1, 100)
    
    # Generate candidate locations
    candidate_locations = [(random.randint(1, m), random.randint(1, n)) for _ in range(k)]
    
    # Construct the input
    input_data = f"{m} {n}\n"
    for row in map_grid:
        input_data += " ".join(map(str, row)) + "\n"
    input_data += f"{k}\n"
    for loc in candidate_locations:
        input_data += f"{loc[0]} {loc[1]}\n"
    
    return input_data

# Example usage:
print(generate_test_case())
```

**Explanation:**
1. **Map dimensions (m, n):** Randomly chosen within the given constraints (1 ≤ m, n ≤ 100).
2. **Map grid:** A \(m \times n\) list of lists where each element is either 0 or 1, representing the absence or presence of a convenience store.
3. **Number of candidate locations (k):** Randomly chosen within the given constraints (1 ≤ k ≤ 100).
4. **Candidate locations:** A list of \(k\) tuples, each representing the coordinates of a candidate location.

The generated test case follows the input format specified in the problem statement. You can use the `generate_test_case` function to create various test cases for your competitive programming problem.

Feel free to modify the constraints and randomization as needed for more specific scenarios or additional testing.