code: public void addVariableMappingForField(DifferentialFunction function, String fieldName, String varName) {
          fieldVariableResolutionMapping.put(function.getOwnName(), fieldName, varName);
      }
docs: Adds a field name -> variable name mapping for a given function.<br>
  This is used for model import where there is an unresolved variable at the time of calling any
  {@link org.nd4j.imports.graphmapper.GraphMapper#importGraph(File)}
  .
  <p>
  This data structure is typically accessed during {@link DifferentialFunction#resolvePropertiesFromSameDiffBeforeExecution()}
  <p>
  When a function attempts to resolve variables right before execution, there needs to be a way of knowing
  which variable in a samediff graph should map to a function's particular field name
  
  @param function  the function to map
  @param fieldName the field name for the function to map
  @param varName   the variable name of the array to get from samediff