/**
* A profile stores personal information about a {@link Sone}. All information
* is optional and can be {@code null}.
/**
* A profile stores personal information about a {@link Sone}. All information
* is optional and can be {@code null}.
public Field addField(String fieldName) throws IllegalArgumentException {
checkNotNull(fieldName, "fieldName must not be null");
checkArgument(fieldName.length() > 0, "fieldName must not be empty");
public Field addField(String fieldName) throws IllegalArgumentException {
checkNotNull(fieldName, "fieldName must not be null");
checkArgument(fieldName.length() > 0, "fieldName must not be empty");