String outname = (isPartialSchema) ? pigFields[i].getName() : inputField.name();
if (outname == null)
outname = FIELD_NAME + "_" + i; // field name cannot be null
/* get doc of output */
String doc = (isPartialSchema) ? pigFields[i].getDescription() : inputField.doc();
JsonNode defaultvalue = (inputField != null) ? inputField.defaultValue() : null;
outFields.add(new Field(outname, fieldSchema, doc, defaultvalue));