Ensure test determinism

Create reliable and reproducible tests by explicitly controlling test inputs and verifying function behavior doesn’t have unintended side effects. Two key practices to follow:

1. When testing functions that shouldn’t modify input parameters, verify the inputs remain unchanged: ```java // Before function call INDArray duplicateInput = inputMatrix.dup();

// Call function under test PCA.pca_factor(inputMatrix, …);

// Verify input wasn’t modified assertEquals(duplicateInput, inputMatrix);

2. Make tests deterministic by setting explicit seeds for any operations involving randomness:
```java
// Use a specific seed to ensure deterministic behavior
MultiLayerConfiguration conf = new NeuralNetConfiguration.Builder()
    .seed(2021) // Important: ensures consistent initialization for tests
    .dataType(DataType.DOUBLE)
    // other configuration
    .build();

Including these practices in your tests will help prevent flaky tests, make debugging easier, and ensure that test failures represent actual issues rather than side effects or randomness.