add : some error messages.

samila/params.py

@@ -27,7 +27,10 @@ NFT_STORAGE_API = "https://api.nft.storage/upload"
 NFT_STORAGE_SUCCESS_MESSAGE = "Everything seems good."
 FIG_SAVE_SUCCESS_MESSAGE = "Everything seems good."
 NO_FIG_ERROR_MESSAGE = "No figure was found. First run `generate` and `plot` methods."
-
+DATA_TYPE_ERROR = "Provided data file is not supported. It should be either file or io.IOBase."
+DATA_PARSING_ERROR = "Provided data format is wrong. It should be in JSON format including data1 and data2 fields."
+JUST_DATA_WARNING = "Just data is provided you can't use generate function."
+NOTHING_PROVIDED_WARNING = "Neither function nor data is provided."
 
 class Projection(Enum):
     """