code: public ConversionHandler from(MappedField sourceMappedField){
  		this.sourceField = sourceMappedField.getValue();
  		placeholders.put(sourceTypePattern, sourceField.getType().getName());
  		placeholders.put(sourceNamePattern, sourceField.getName());
  		placeholders.put(sourceGetPattern, sourceMappedField.getMethod());
  		placeholders.put(sourceSetPattern, sourceMappedField.setMethod());
  		return this;
  	}
docs: Source field definition.
  @param sourceMappedField source field
  @return this instance of ConversionHandler