 Preprocessing
 
 In the preprocessing phase, both the title and the text of the news are concatenated using a separator `[SEP]`.
 This makes the full text as:
 
 ```
 [CLS] Title Sentence [SEP] News text body [SEP]
 ```
 
 The data are splitted according to the following ratio:
 - Training set 60%.
 - Validation set 20%.
 - Test set 20%.
 
 Lables are mapped as: `{fake: 0, true: 1}`
 
 