human
Solve the following python programming problem given the following code:
# Example Defaults from LamAna.models.Wilson_LT
class Defaults(BaseDefaults):
    '''Return parameters for building distributions cases.  Useful for consistent 
    testing.
    
    Dimensional defaults are inheirited from utils.BaseDefaults().  
    Material-specific parameters are defined here by he user.
    
    - Default geometric and materials parameters
    - Default FeatureInputs
    
    Examples
    ========
    >>>dft = Defaults()
    >>>dft.load_params
    {'R' : 12e-3, 'a' : 7.5e-3, 'p' : 1, 'P_a' : 1, 'r' : 2e-4,}
    
    >>>dft.mat_props
    {'Modulus': {'HA': 5.2e10, 'PSu': 2.7e9},
    'Poissons': {'HA': 0.25, 'PSu': 0.33}}
    
    >>>dft.FeatureInput
     {'Geometry' : '400-[200]-800',
      'Geometric' : {'R' : 12e-3, 'a' : 7.5e-3, 'p' : 1, 'P_a' : 1, 'r' : 2e-4,},
      'Materials' : {'HA' : [5.2e10, 0.25], 'PSu' : [2.7e9, 0.33],},
      'Custom' : None,
      'Model' : Wilson_LT,
     }

    '''
    def __init__(self):
        BaseDefaults.__init__(self)
        '''DEV: Add defaults first.  Then adjust attributes.'''
        # DEFAULTS ------------------------------------------------------------
        # Build dicts of geometric and material parameters
        self.load_params = {'R' : 12e-3,                   # specimen radius
                            'a' : 7.5e-3,                  # support ring radius
                            'p' : 5,                       # points/layer
                            'P_a' : 1,                     # applied load 
                            'r' : 2e-4,                    # radial distance from center loading
                            }

        self.mat_props = {'Modulus': {'HA': 5.2e10, 'PSu': 2.7e9},
                           'Poissons': {'HA': 0.25, 'PSu': 0.33}}
        
        # ATTRIBUTES ----------------------------------------------------------                
        # FeatureInput
        self.FeatureInput = self.get_FeatureInput(self.Geo_objects['standard'][0], 
                                            ...
Given the above code, generate some markdown instructions for it.
assistant
#Here is the Python program you requested.

The latter geometric defaults come out of the box when subclassed from BaseDefaults.  If custom geometries are desired, the user can override the geo_inputs dict, which automatically builds the Geo_objects dict.
Users can override three categories of defaults parameters:

geometric variables
loading parameters
material properties

As mentioned, some geometric variables are provided for general laminate dimensions.  The other parameters cannot be predicted and need to be defined by the user. Below is an example of a Defaults() subclass.  If a custom model has been implemented (see next section), it is convention to place Defaults() and all other custom code within this module.  If a custom model is implemented an located in the models directory, Cases will automatically search will the designated model modules, locate the load_params and mat_props attributes and load them automatically for all Cases instantiations.