Apply fixes from StyleCI

[yunwuxin]

This pull request applies code style fixes from an analysis carried out by StyleCI.

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For more information, click here.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 6.53153% with 415 lines in your changes are missing coverage. Please review.

Project coverage is 12.24%. Comparing base (e35f497) to head (a0bfe55).

Files	Patch %	Lines
src/model/concern/RelationShip.php	0.00%	61 Missing :warning:
src/db/BaseQuery.php	4.87%	39 Missing :warning:
src/db/connector/Mongo.php	0.00%	39 Missing :warning:
src/model/relation/HasManyThrough.php	0.00%	39 Missing :warning:
src/model/concern/Attribute.php	0.00%	26 Missing :warning:
src/model/relation/BelongsTo.php	0.00%	21 Missing :warning:
src/model/relation/HasOne.php	0.00%	18 Missing :warning:
src/model/relation/MorphTo.php	0.00%	17 Missing :warning:
src/model/relation/HasMany.php	0.00%	15 Missing :warning:
src/Paginator.php	0.00%	14 Missing :warning:
... and 21 more

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Additional details and impacted files

@@            Coverage Diff            @@
##                3.0     #522   +/-   ##
=========================================
  Coverage     12.24%   12.24%           
  Complexity     2965     2965           
=========================================
  Files            64       64           
  Lines          7129     7129           
=========================================
  Hits            873      873           
  Misses         6256     6256           

Flag	Coverage Δ
unittests	12.24% <6.53%> (ø)

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