PDFImpl
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Definition::

    uint8 GAUSSIAN=1
    uint8 UNIFORM=2
    uint8 DISJUNCTION_STRING = 3  # PMF
    uint8 DISJUNCTION_FLOAT = 4   # PMF
    uint8 DISJUNCTION_PDF = 5     # Mixture
    uint8 CONJUNCTION = 6
    
    uint8 type
    uint32 num_dimensions
    DimensionDescription[] dimensions
    
    # Gaussian
    float64[] mean
    float64[] covariance
    
    # Uniform
    float64 density
    
    # For both mixture and discrete 
    float64[] probabilities
    
    # mixture of PFDs (conjunction or disjunction)
    uint32[] sub_pdf_ptrs
    
    # discrete
    int32 domain_size
    float64[] values_float
    string[] values_string